Adjust testcase for PIE compilers

one some systems GCC defaults to PIC/PIE code which is incompatible
with a unannotated asm call to a function (getenv here).  TCC doesn't
support these PIC annotations (yet), so play some pre-processor games.

tests/tcctest.c

@@ -3358,7 +3358,13 @@ void test_asm_call(void)
      or libraries.  We chose getenv here, which isn't used anywhere else
      in this file.  (If we used e.g. printf, which is used we already
      would have a global symbol entry, not triggering the bug which is
-     tested here).  */
+     tested here).  */
+  /* two pushes so stack remains aligned */
+  asm volatile ("push %%rdi; push %%rdi; mov %0, %%rdi;"
+#if 1 && !defined(__TINYC__) && (defined(__PIC__) || defined(__PIE__))
+		"call getenv@plt;"
+#else
+		"call getenv;"
 #endif
 		"pop %%rdi; pop %%rdi"
 		: "=a" (s) : "r" (str));