Make improvements

- Improve compatibility with Blink virtual machine
- Add non-POSIX APIs for joining threads and signal masks
- Never ever use anything except 32-bit integers for atomics
- Add some `#undef` statements to workaround `ctags` problems

libc/intrin/describentfileshareflags.c

@@ -20,13 +20,17 @@
 #include "libc/macros.internal.h"
 #include "libc/nt/enum/filesharemode.h"
 
+#ifdef DescribeNtFileShareFlags
+#undef DescribeNtFileShareFlags
+#endif
+
 static const struct DescribeFlags kFileShareflags[] = {
     {kNtFileShareRead, "Read"},      //
     {kNtFileShareWrite, "Write"},    //
     {kNtFileShareDelete, "Delete"},  //
 };
 
-const char *(DescribeNtFileShareFlags)(char buf[64], uint32_t x) {
+const char *DescribeNtFileShareFlags(char buf[64], uint32_t x) {
   return DescribeFlags(buf, 64, kFileShareflags, ARRAYLEN(kFileShareflags),
                        "kNtFileShare", x);
 }