WAIT/POST_SEM(): generalize interface (and more)

Currently used only with 'tcc_compile_sem' to protect
tcc_compile(),  but can be used with other semaphores

Also fix deadlock when tcc_enter_state() is called
recursively for the same state, for example with
tcc_warning() from #pragma comment(option,"...")

Also:
- libtcc.c: error1(): use cstr_[v]printf()
- tcc.h: set TCC_USING_DOUBLE_FOR_LDOUBLE for macho-arm64
  (rather than for macho-X86_64)
- tcc.h: define TCC_TARGET_MACHO on __APPLE__ by default
- tcc.h: cleanup TCCState, move DEFASM token stuff to tcctok.h
- tccgen.c: more static
- Makefile/tcc.c: review githash
- tccpe/tcctools: use read() instead of fgets() in pe_load_def()
  (all files opened by tcc for reading are now read via 'int fd')
- configure/win32: don't preset CONFIG_TCCDIR (to allow to override it)
- tcc.c -bench: do not include output/run-time

tcctools.c

@@ -385,10 +385,8 @@ usage:
     ret = 0;
 
 the_end:
-    /* cannot free memory received from tcc_get_dllexports
-       if it came from a dll */
-    /* if (p)
-        tcc_free(p); */
+    if (p)
+        tcc_free(p);
     if (fp)
         fclose(fp);
     if (op)