[build] silence some useless gcc warnings

Author: vtjnash

src/Makefile

@@ -21,7 +21,7 @@ FLAGS := \
 	-I$(JULIAHOME)/deps/valgrind
 ifneq ($(USEMSVC), 1)
 FLAGS += -Wall -Wno-strict-aliasing -fno-omit-frame-pointer -fvisibility=hidden -fno-common \
-		 -Wpointer-arith -Wundef
+		 -Wno-comment -Wpointer-arith -Wundef
 ifeq ($(USEGCC),1) # GCC bug #25509 (void)__attribute__((warn_unused_result))
 FLAGS += -Wno-unused-result
 endif

src/llvm-version.h

@@ -17,3 +17,8 @@
 #endif
 
 #define LLVM_DISABLE_ABI_BREAKING_CHECKS_ENFORCING 0
+
+#if defined(__GNUC__) && (__GNUC__ >= 9)
+// Added in GCC 9, this warning is annoying
+#pragma GCC diagnostic ignored "-Winit-list-lifetime"
+#endif