qemu-plugin.h: remove GCC < 4

Since commit efc6c07 ("configure: Add a test for the minimum compiler
version"), QEMU explicitely depends on GCC >= 4.8.

(clang >= 3.4 advertizes itself as GCC >= 4.2 compatible)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201210134752.780923-5-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qemu/qemu-plugin.h

@@ -28,13 +28,8 @@
   #endif
   #define QEMU_PLUGIN_LOCAL
 #else
-  #if __GNUC__ >= 4
-    #define QEMU_PLUGIN_EXPORT __attribute__((visibility("default")))
-    #define QEMU_PLUGIN_LOCAL  __attribute__((visibility("hidden")))
-  #else
-    #define QEMU_PLUGIN_EXPORT
-    #define QEMU_PLUGIN_LOCAL
-  #endif
+  #define QEMU_PLUGIN_EXPORT __attribute__((visibility("default")))
+  #define QEMU_PLUGIN_LOCAL  __attribute__((visibility("hidden")))
 #endif
 
 typedef uint64_t qemu_plugin_id_t;