Revert "mjit_worker.c: try passing -nostdlib to AIX"

This reverts commit b32fb23083.

This didn't work on AIX.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66823 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

mjit_worker.c

@@ -247,9 +247,9 @@ static char *libruby_pathflag;
 # define MJIT_CFLAGS_PIPE 0
 #endif
 
-// Use `-nodefaultlibs -nostdlib` for GCC where possible, which does not work on mingw and cygwin.
+// Use `-nodefaultlibs -nostdlib` for GCC where possible, which does not work on mingw, cygwin and AIX.
 // This seems to improve MJIT performance on GCC.
-#if defined __GNUC__ && !defined __clang__ && !defined(_WIN32) && !defined(__CYGWIN__)
+#if defined __GNUC__ && !defined __clang__ && !defined(_WIN32) && !defined(__CYGWIN__) && !defined(_AIX)
 # define GCC_NOSTDLIB_FLAGS "-nodefaultlibs", "-nostdlib",
 #else
 # define GCC_NOSTDLIB_FLAGS /* empty */