fix #1246 (#1254)

* fix finding python path which only has python3.

* fix #1246, arm host issue.

* skip assembler tests on non-x86 host.

* update macro of dummy value.

* fix MSVC macro.

* update dummy array value macro.

* restore to original qemu code.

tests/unit/test_mem_high.c

@@ -92,6 +92,9 @@ static void test_high_address_read_values(void **state)
     uc_engine *uc = *state;
     struct stat info;
     char * code = read_file("high_address.bin", &info);
+    if (code == NULL) {
+        return;
+    }
 
     uint64_t addr = 0x0010000000000001; 
     //addr = 0x000ffffffffffff8; // uncomment to fix wrong behaviour