Add chibicc

This program popped up on Hacker News recently. It's the only modern
compiler I've ever seen that doesn't have dependencies and is easily
modified. So I added all of the missing GNU extensions I like to use
which means it might be possible soon to build on non-Linux and have
third party not vendor gcc binaries.

libc/stdio/g_stderr.c

@@ -24,7 +24,7 @@ STATIC_YOINK("_init_g_stderr");
 
 FILE *stderr;
 hidden FILE g_stderr;
-hidden unsigned char g_stderr_buf[BUFSIZ] aligned(PAGESIZE);
+hidden unsigned char g_stderr_buf[BUFSIZ] forcealign(PAGESIZE);
 
 static textstartup void _init_g_stderr2() {
   _fflushregister(stderr);

libc/stdio/g_stdin.c

@@ -24,7 +24,7 @@ STATIC_YOINK("_init_g_stdin");
 
 FILE *stdin;
 hidden FILE g_stdin;
-hidden unsigned char g_stdin_buf[BUFSIZ] aligned(PAGESIZE);
+hidden unsigned char g_stdin_buf[BUFSIZ] forcealign(PAGESIZE);
 
 static textstartup void g_stdin_init() {
   _fflushregister(stdin);

libc/stdio/g_stdout.c

@@ -27,7 +27,7 @@ STATIC_YOINK("_init_g_stdout");
 
 FILE *stdout;
 hidden FILE g_stdout;
-hidden unsigned char g_stdout_buf[BUFSIZ] aligned(PAGESIZE);
+hidden unsigned char g_stdout_buf[BUFSIZ] forcealign(PAGESIZE);
 
 static textstartup void _init_g_stdout2() {
   struct FILE *sf;

libc/stdio/mkstemp.c

@@ -19,4 +19,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/temp.h"
 
-int mkstemp(char *template) { return mkostempsm(template, 0, 0, 0600); }
+int mkstemp(char *template) {
+  return mkostempsm(template, 0, 0, 0600);
+}