configure: cleanup

- add quotes: eval opt=\"$opt\"
- use $source_path/conftest.c for OOT build
- add fn_makelink() for OOT build
- do not check lddir etc. on Windows/MSYS
- formatting

config-print.c
- rename to conftest.c (for consistency)
- change option e to b
- change output from that from "yes" to "no"
- remove inttypes.h dependency
- simpify version output

Makefile:
- improve GCC warning flag checks

tcc.h:
- add back default CONFIG_LDDIR
- add default CONFIG_TCCDIR also (just for fun)

tccpp.c:
- fix Christian's last warning
  tccpp.c: In function ‘macro_subst’:
  tccpp.c:2803:12: warning: ‘*((void *)&cval+4)’ is used uninitialized
     in this function [-Wuninitialized]
  That the change fixes the warning doesn't make sense but anyway.

libtcc.c:
- tcc_error/warning: print correct source filename/line for
  token :paste: (also inline :asm:)

lddir and multiarch logic still needs fixing.

conftest.c

@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+    switch(argc == 2 ? argv[1][0] : 0) {
+#ifdef __GNUC__
+        case 'v':
+            printf("%d\n", __GNUC__);
+            break;
+        case 'm':
+            printf("%d\n", __GNUC_MINOR__);
+            break;
+#else
+        case 'v':
+        case 'm':
+            puts("0");
+            break;
+#endif
+        case 'b':
+        {
+            volatile unsigned foo = 0x01234567;
+            puts(*(unsigned char*)&foo == 0x67 ? "no" : "yes");
+            break;
+        }
+        case -1:
+            /* to test -Wno-unused-result */
+            fread(NULL, 1, 1, NULL);
+            break;
+    }
+    return 0;
+}