[libomptarget] Fixed MSVC build fail caused by __attribute__((used)).

Differential Revision: https://reviews.llvm.org/D97348

GitOrigin-RevId: 6baeeb9efa8ec6d64d66fdceac7240b5b08fb40b
diff --git a/libomptarget/include/Debug.h b/libomptarget/include/Debug.h
index 9585184..3710192 100644
--- a/libomptarget/include/Debug.h
+++ b/libomptarget/include/Debug.h
@@ -53,8 +53,17 @@
   OMP_INFOTYPE_ALL = 0xffffffff,
 };
 
+#define GCC_VERSION                                                            \
+  (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+
+#if !defined(__clang__) && defined(__GNUC__) && GCC_VERSION < 70100
+#define USED __attribute__((used))
+#else
+#define USED
+#endif
+
 // Add __attribute__((used)) to work around a bug in gcc 5/6.
-static inline uint32_t __attribute__((used)) getInfoLevel() {
+USED static inline uint32_t getInfoLevel() {
   static uint32_t InfoLevel = 0;
   static std::once_flag Flag{};
   std::call_once(Flag, []() {
@@ -66,7 +75,7 @@
 }
 
 // Add __attribute__((used)) to work around a bug in gcc 5/6.
-static inline uint32_t __attribute__((used)) getDebugLevel() {
+USED static inline uint32_t getDebugLevel() {
   static uint32_t DebugLevel = 0;
   static std::once_flag Flag{};
   std::call_once(Flag, []() {
@@ -77,6 +86,9 @@
   return DebugLevel;
 }
 
+#undef USED
+#undef GCC_VERSION
+
 #ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS
 #endif