Add automatic TMPDIR setup/teardown to GNU Make

We now guarantee TMPDIR will be defined on a per build rule basis. It'll
be an absolute path. It'll be secure and unique. It'll be rm -rf'd after
the last shell script line in your build rule is executed. If $TMPDIR is
already defined, then it'll be created as a subdirectory of your $TMPDIR
and then replace the variable with the new definition. The Landlock Make
repository will be updated with examples shortly after this change which
shall be known as Landlock Make 1.1.1.

See #530

test/libc/calls/mkntpath_test.c

@@ -50,3 +50,8 @@ TEST(mkntpath, testRemoveDoubleSlash) {
   EXPECT_EQ(8, __mkntpath("\\\\?\\doge", p));
   EXPECT_STREQ(u"\\\\?\\doge", p);
 }
+
+TEST(mkntpath, testJustC) {
+  EXPECT_EQ(7, __mkntpath("/C", p));
+  EXPECT_STREQ(u"\\\\?\\C:\\", p);
+}

test/libc/str/strcmp_test.c

@@ -534,8 +534,8 @@ void longstringislong_dupe(size_t size, char data[size], char dupe[size]) {
 BENCH(bench_00_strcmp, bench) {
   size_t size;
   char *dupe, *data;
-  size = ROUNDDOWN(MAX(FRAMESIZE, getcachesize(kCpuCacheTypeData, 1)) / 2,
-                   PAGESIZE);
+
+  size = 14139;
   data = gc(malloc(size));
   dupe = gc(malloc(size));
 
@@ -576,8 +576,7 @@ BENCH(bench_00_strcmp, bench) {
 BENCH(bench_01_strcasecmp, bench) {
   size_t size;
   char *dupe, *data;
-  size = ROUNDDOWN(MAX(FRAMESIZE, getcachesize(kCpuCacheTypeData, 1)) / 2,
-                   PAGESIZE);
+  size = 141393;
   data = gc(malloc(size));
   dupe = gc(malloc(size));
 

test/libc/tinymath/fmod_test.c

@@ -17,8 +17,8 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/math.h"
-#include "libc/stdio/rand.h"
 #include "libc/runtime/gc.internal.h"
+#include "libc/stdio/rand.h"
 #include "libc/testlib/ezbench.h"
 #include "libc/testlib/testlib.h"
 #include "libc/x/x.h"
@@ -67,7 +67,19 @@ TEST(fmodf, test) {
   EXPECT_STREQ("8e+20", gc(xdtoaf(fmodf(8e20, 32e20))));
 }
 
-BENCH(fmod, bench) {
-  EZBENCH2("fmod eze", donothing, fmodl(8, 32));
-  EZBENCH2("fmod big", donothing, fmodl(5.319372648326541e+255, M_2_PI));
+BENCH(fmodf, bench) {
+  EZBENCH2("fmodf eze", donothing, fmodf(8, 32));
+  EZBENCH2("fmodf big", donothing, fmodf(5.319372648326541e+255, M_2_PI));
+}
+
+BENCH(fmod, bench) {
+  // fmod-tiny.S goes slow in the average case, fast for big case
+  EZBENCH2("fmod eze", donothing, fmod(8, 32));
+  // fmod.c goes fast for the average case very slow for big case
+  EZBENCH2("fmod big", donothing, fmod(5.319372648326541e+255, M_2_PI));
+}
+
+BENCH(fmodl, bench) {
+  EZBENCH2("fmodl eze", donothing, fmodl(8, 32));
+  EZBENCH2("fmodl big", donothing, fmodl(5.319372648326541e+255, M_2_PI));
 }

test/tool/net/lunix_test.lua

@@ -14,7 +14,7 @@
 -- PERFORMANCE OF THIS SOFTWARE.
 
 gotsigusr1 = false
-tmpdir = "o/tmp/lunix_test.%d" % {unix.getpid()}
+tmpdir = "%s/o/tmp/lunix_test.%d" % {os.getenv('TMPDIR'), unix.getpid()}
 
 function string.starts(String,Start)
    return string.sub(String,1,string.len(Start))==Start

test/tool/net/slurp_test.lua

@@ -13,7 +13,7 @@
 -- TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 -- PERFORMANCE OF THIS SOFTWARE.
 
-tmpdir = "o/tmp/lunix_test.%d" % {unix.getpid()}
+tmpdir = "%s/o/tmp/lunix_test.%d" % {os.getenv('TMPDIR'), unix.getpid()}
 
 local function Path(name)
    return tmpdir .. '/' .. name