Bring back gc() function

Renaming gc() to _gc() was a mistake since the better thing to do is put
it behind the _COSMO_SOURCE macro. We need this change because I haven't
wanted to use my amazing garbage collector ever since we renamed it. You
now need to define _COSMO_SOURCE yourself when using amalgamation header
and cosmocc users need to pass the -mcosmo flag to get the gc() function

Some other issues relating to cancelation have been fixed along the way.
We're also now putting cosmocc in a folder named `.cosmocc` so it can be
more safely excluded by grep --exclude-dir=.cosmocc --exclude-dir=o etc.

third_party/python/Modules/_decimal/libmpdec/transpose.c

@@ -28,7 +28,7 @@
 │ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                           │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "third_party/python/Modules/_decimal/libmpdec/transpose.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "third_party/python/Modules/_decimal/libmpdec/bits.h"
 #include "third_party/python/Modules/_decimal/libmpdec/constants.h"

third_party/python/Modules/_threadmodule.c

@@ -27,7 +27,7 @@
 #include "libc/errno.h"
 #include "libc/log/log.h"
 #include "libc/mem/alg.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/nt/createfile.h"
 #include "libc/nt/dll.h"
 #include "libc/nt/enum/creationdisposition.h"

third_party/python/Modules/getpath.c

@@ -11,7 +11,7 @@
 #include "libc/intrin/cmpxchg.h"
 #include "libc/log/log.h"
 #include "libc/mem/alloca.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"

third_party/python/Modules/posixmodule.c

@@ -29,7 +29,7 @@
 #include "libc/errno.h"
 #include "libc/log/log.h"
 #include "libc/mem/alg.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/nt/createfile.h"
 #include "libc/nt/dll.h"
 #include "libc/nt/enum/creationdisposition.h"

third_party/python/Modules/selectmodule.c

@@ -7,7 +7,7 @@
 #include "libc/calls/calls.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/nt/efi.h"
 #include "libc/sock/epoll.h"

third_party/python/Modules/tlsmodule.c

@@ -20,7 +20,7 @@
 #include "libc/calls/calls.h"
 #include "libc/errno.h"
 #include "libc/macros.internal.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/str/str.h"
 #include "net/https/https.h"
 #include "third_party/mbedtls/ctr_drbg.h"

third_party/python/Objects/listobject.c

@@ -6,7 +6,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/mem/mem.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "third_party/python/Include/abstract.h"
 #include "third_party/python/Include/accu.h"
 #include "third_party/python/Include/boolobject.h"

third_party/python/Python/import.c

@@ -886,7 +886,7 @@ PyImport_ExecCodeModuleWithPathnames(const char *name, PyObject *co,
     else if (cpathobj != NULL) {
         // cpathobj != NULL means cpathname != NULL
         size_t cpathlen = strlen(cpathname);
-        char *pathname2 = _gc(strdup(cpathname));
+        char *pathname2 = gc(strdup(cpathname));
         if (_endswith(pathname2, ".pyc"))
         {
             pathname2[cpathlen-2] = '\0'; // so now ends with .py
@@ -2152,7 +2152,7 @@ static PyObject *_imp_path_isdir(PyObject *module, PyObject *arg) {
   Py_ssize_t n;
   const char *path;
   if (!PyArg_Parse(arg, "z#:_path_isdir", &path, &n)) return 0;
-  if (path == NULL) path = _gc(getcwd(NULL, 0));
+  if (path == NULL) path = gc(getcwd(NULL, 0));
   return _check_path_mode(path, S_IFDIR);
 }
 PyDoc_STRVAR(_imp_path_isdir_doc, "check if path is dir");
@@ -2172,7 +2172,7 @@ static PyObject *_imp_calc_mtime_and_size(PyObject *module, PyObject *arg) {
   Py_ssize_t n;
   const char *path;
   if (!PyArg_Parse(arg, "z#:_calc_mtime_and_size", &path, &n)) return 0;
-  if (path == NULL) path = _gc(getcwd(NULL, 0));
+  if (path == NULL) path = gc(getcwd(NULL, 0));
   if (stat(path, &stinfo))
     return PyTuple_Pack(2, PyLong_FromLong((long)-1), PyLong_FromLong((long)0));
   return PyTuple_Pack(2, PyLong_FromLong((long)stinfo.st_mtime),
@@ -2774,7 +2774,7 @@ static PyObject *CosmoImporter_find_spec(PyObject *cls, PyObject **args,
    */
 
   newpathsize = sizeof(basepath) + cnamelen + sizeof("/__init__.pyc") + 1;
-  newpath = _gc(malloc(newpathsize));
+  newpath = gc(malloc(newpathsize));
   bzero(newpath, newpathsize);
   /* performing a memccpy sequence equivalent to:
    * snprintf(newpath, newpathsize, "/zip/.python/%s.pyc", cname); */

third_party/python/Python/marshal.c

@@ -9,7 +9,7 @@
 #include "libc/calls/calls.h"
 #include "libc/calls/weirdtypes.h"
 #include "libc/mem/mem.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "third_party/python/Include/abstract.h"
 #include "third_party/python/Include/boolobject.h"
 #include "third_party/python/Include/code.h"

third_party/python/Python/sysmodule.c

@@ -6,7 +6,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/dce.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/nt/dll.h"
 #include "libc/nt/version.h"

third_party/python/pycomp.c

@@ -118,15 +118,15 @@ main(int argc, char *argv[])
     GetOpts(argc, argv);
     marshalled = 0;
     if (stat(inpath, &st) == -1) perror(inpath), exit(1);
-    CHECK_NOTNULL((p = _gc(xslurp(inpath, &n))));
+    CHECK_NOTNULL((p = gc(xslurp(inpath, &n))));
     Py_NoUserSiteDirectory++;
     Py_NoSiteFlag++;
     Py_IgnoreEnvironmentFlag++;
     Py_FrozenFlag++;
     /* Py_VerboseFlag++; */
-    Py_SetProgramName(_gc(utf8to32(argv[0], -1, 0)));
+    Py_SetProgramName(gc(utf8to32(argv[0], -1, 0)));
     _Py_InitializeEx_Private(1, 0);
-    name = _gc(xjoinpaths("/zip/.python", StripComponents(inpath, 3)));
+    name = gc(xjoinpaths("/zip/.python", StripComponents(inpath, 3)));
     code = Py_CompileStringExFlags(p, name, Py_file_input, NULL, optimize);
     if (!code) goto error;
     marshalled = PyMarshal_WriteObjectToString(code, Py_MARSHAL_VERSION);

third_party/python/pyobj.c

@@ -25,7 +25,7 @@
 #include "libc/log/check.h"
 #include "libc/log/log.h"
 #include "libc/macros.internal.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/stack.h"

third_party/python/runpythonmodule.c

@@ -17,7 +17,7 @@
 #include "libc/log/check.h"
 #include "libc/log/log.h"
 #include "libc/macros.internal.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/runtime/symbols.internal.h"