Avoid error messages when building with Clang.

src/Makefile

@@ -290,15 +290,15 @@ ifeq (Windows,$(TARGET_SYS))
   TARGET_XSHLDFLAGS= -shared
   TARGET_DYNXLDOPTS=
 else
+ifeq (,$(shell $(TARGET_CC) -o /dev/null -c -x c /dev/null -fno-stack-protector 2>/dev/null || echo 1))
+  TARGET_XCFLAGS+= -fno-stack-protector
+endif
 ifeq (Darwin,$(TARGET_SYS))
   ifeq (,$(MACOSX_DEPLOYMENT_TARGET))
     export MACOSX_DEPLOYMENT_TARGET=10.4
   endif
   TARGET_STRIP+= -x
   TARGET_AR+= 2>/dev/null
-  ifeq (,$(shell $(TARGET_CC) -o /dev/null -c -x c /dev/null -fno-stack-protector 2>/dev/null || echo 1))
-    TARGET_XCFLAGS+= -fno-stack-protector
-  endif
   TARGET_XSHLDFLAGS= -dynamiclib -single_module -undefined dynamic_lookup -fPIC
   TARGET_DYNXLDOPTS=
   TARGET_XSHLDFLAGS+= -install_name $(TARGET_DYLIBPATH) -compatibility_version $(MAJVER).$(MINVER) -current_version $(MAJVER).$(MINVER).$(RELVER)
@@ -310,14 +310,10 @@ else
 ifeq (iOS,$(TARGET_SYS))
   TARGET_STRIP+= -x
   TARGET_AR+= 2>/dev/null
-  TARGET_XCFLAGS+= -fno-stack-protector
   TARGET_XSHLDFLAGS= -dynamiclib -single_module -undefined dynamic_lookup -fPIC
   TARGET_DYNXLDOPTS=
   TARGET_XSHLDFLAGS+= -install_name $(TARGET_DYLIBPATH) -compatibility_version $(MAJVER).$(MINVER) -current_version $(MAJVER).$(MINVER).$(RELVER)
 else
-  ifneq (,$(findstring stack-protector,$(shell $(TARGET_CC) -dumpspecs)))
-    TARGET_XCFLAGS+= -fno-stack-protector
-  endif
   ifneq (SunOS,$(TARGET_SYS))
     ifneq (PS3,$(TARGET_SYS))
       TARGET_XLDFLAGS+= -Wl,-E