[Msan] Make the obstack.cc test Linux-specific

[eugenis]

LGTM

test/msan/Linux/obstack.cc

+// RUN: %clangxx_msan -O0 -g %s -o %t && %run %t
+// RUN: %clangxx_msan -O0 -g -DPOSITIVE %s -o %t && not %run %t |& FileCheck %s
+
+#include <obstack.h>
+#include <sanitizer/msan_interface.h>
+#include <stdlib.h>
+
+static void *obstack_chunk_alloc(size_t sz) {
+  return malloc(sz);
+}
+
+static void obstack_chunk_free(void *p) {
+  free(p);
+}
+
+int main(void) {
+  obstack obs;
+  obstack_init(&obs);
+  for (size_t sz = 16; sz < 0xFFFF; sz *= 2) {
+    void *p = obstack_alloc(&obs, sz);
+    int data[10] = {0};
+    obstack_grow(&obs, &data, sizeof(data));
+    obstack_blank(&obs, sz);
+    obstack_grow(&obs, &data, sizeof(data));
+    obstack_int_grow(&obs, 13);
+    p = obstack_finish(&obs);
+#ifdef POSITIVE
+    if (sz == 4096) {
+      __msan_check_mem_is_initialized(p, sizeof(data));
+      __msan_check_mem_is_initialized(p, sizeof(data) + 1);
+    }
+    // CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value
+    // CHECK: #0 0x{{.*}} in main{{.*}}obstack.cc:[[@LINE-30]]
+#endif
+  }
+  obstack_free(&obs, 0);
+}

test/msan/obstack.cc

-// RUN: %clangxx_msan -O0 -g %s -o %t && %run %t
-// RUN: %clangxx_msan -O0 -g -DPOSITIVE %s -o %t && not %run %t |& FileCheck %s
-
-#include <obstack.h>
-#include <sanitizer/msan_interface.h>
-#include <stdlib.h>
-
-static void *obstack_chunk_alloc(size_t sz) {
-  return malloc(sz);
-}
-
-static void obstack_chunk_free(void *p) {
-  free(p);
-}
-
-int main(void) {
-  obstack obs;
-  obstack_init(&obs);
-  for (size_t sz = 16; sz < 0xFFFF; sz *= 2) {
-    void *p = obstack_alloc(&obs, sz);
-    int data[10] = {0};
-    obstack_grow(&obs, &data, sizeof(data));
-    obstack_blank(&obs, sz);
-    obstack_grow(&obs, &data, sizeof(data));
-    obstack_int_grow(&obs, 13);
-    p = obstack_finish(&obs);
-#ifdef POSITIVE
-    if (sz == 4096) {
-      __msan_check_mem_is_initialized(p, sizeof(data));
-      __msan_check_mem_is_initialized(p, sizeof(data) + 1);
-    }
-    // CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value
-    // CHECK: #0 0x{{.*}} in main{{.*}}obstack.cc:[[@LINE-30]]
-#endif
-  }
-  obstack_free(&obs, 0);
-}