Introduce #include <cosmo.h> to toolchain users

This change improves the way internal APIs are being hidden behind the
`COSMO` define. The cosmo.h header will take care of defining that, so
that a separate define statement isn't needed. This change also does a
lot more to define which APIs are standard, and which belong to Cosmo.

examples/auto-launch-gdb-on-crash.c

@@ -7,7 +7,7 @@
 │   • http://creativecommons.org/publicdomain/zero/1.0/            │
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
-#include "libc/log/log.h"
+#include "libc/runtime/runtime.h"
 
 /**
  * Automatically launches GDB Debugger TUI during crash.

examples/clock.c

@@ -8,7 +8,7 @@
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
 #include "libc/calls/struct/timespec.h"
-#include "libc/log/log.h"
+#include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/time/time.h"
 

examples/crashreport.c

@@ -8,8 +8,8 @@
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
 #include "libc/intrin/kprintf.h"
-#include "libc/log/log.h"
 #include "libc/math.h"
+#include "libc/runtime/runtime.h"
 #include "libc/runtime/symbols.internal.h"
 
 /**

examples/crashreport2.c

@@ -9,7 +9,7 @@
 #endif
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/sigset.h"
-#include "libc/log/log.h"
+#include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 
 /**

examples/nesemu1.cc

@@ -41,7 +41,7 @@
 #include "libc/time/time.h"
 #include "libc/x/xasprintf.h"
 #include "libc/x/xsigaction.h"
-#include "libc/zip.h"
+#include "libc/zip.internal.h"
 #include "libc/zipos/zipos.internal.h"
 #include "third_party/getopt/getopt.h"
 #include "third_party/libcxx/vector"

examples/stackoverflow.c

@@ -10,7 +10,7 @@
 #include "libc/calls/calls.h"
 #include "libc/limits.h"
 #include "libc/log/check.h"
-#include "libc/log/log.h"
+#include "libc/runtime/runtime.h"
 #include "libc/runtime/stack.h"
 #include "libc/stdio/stdio.h"
 #include "libc/sysv/consts/prot.h"

examples/symtab.c

@@ -8,7 +8,7 @@
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
 #include "libc/intrin/kprintf.h"
-#include "libc/log/log.h"
+#include "libc/runtime/runtime.h"
 
 /**
  * @fileoverview example of how to embed symbol table in .com file