Abstract optnone compiler attribute

GNU compiler doesn't support optnone attribute.

pal/src/exception/seh-unwind.cpp:449:77: warning: ‘optnone’ attribute directive ignored [-Wattributes]

Author: franksinankaya

src/pal/inc/pal.h

@@ -176,6 +176,14 @@ typedef void * NATIVE_LIBRARY_HANDLE;
 #endif
 #endif
 
+#ifndef NOOPT_ATTRIBUTE
+#if defined(_MSC_VER) || defined(__llvm__)
+#define NOOPT_ATTRIBUTE optnone
+#else
+#define NOOPT_ATTRIBUTE optimize("O0")
+#endif
+#endif
+
 #ifndef PAL_STDCPP_COMPAT
 
 #if __GNUC__

src/pal/src/exception/seh-unwind.cpp

@@ -444,7 +444,7 @@ PAL_FreeExceptionRecords(IN EXCEPTION_RECORD *exceptionRecord, IN CONTEXT *conte
 --*/
 PAL_NORETURN
 __attribute__((noinline))
-__attribute__((optnone))
+__attribute__((NOOPT_ATTRIBUTE))
 static void 
 RtlpRaiseException(EXCEPTION_RECORD *ExceptionRecord, CONTEXT *ContextRecord)
 {

src/pal/src/init/pal.cpp

@@ -239,7 +239,7 @@ PAL_SetInitializeDLLFlags(
   real life scenarios work.
 
 --*/
-__attribute__((noinline,optnone))
+__attribute__((noinline,NOOPT_ATTRIBUTE))
 void
 EnsureStackSize(SIZE_T stackSize)
 {

src/pal/tests/palsuite/exception_handling/pal_sxs/test1/dlltest1.cpp

@@ -21,7 +21,7 @@ int InitializeDllTest1()
     return PAL_InitializeDLL();
 }
 
-__attribute__((noinline,optnone))
+__attribute__((noinline,NOOPT_ATTRIBUTE))
 static void FailingFunction(volatile int *p)
 {
     if (p == NULL)

src/pal/tests/palsuite/exception_handling/pal_sxs/test1/dlltest2.cpp

@@ -21,7 +21,7 @@ int InitializeDllTest2()
     return PAL_InitializeDLL();
 }
 
-__attribute__((noinline,optnone))
+__attribute__((noinline,NOOPT_ATTRIBUTE))
 static void FailingFunction(volatile int *p)
 {
     if (p == NULL)