translate-all: Mark map_exec() with the 'unused' attribute

Mark map_exec() with the 'unused' attribute to avoid '-Wunused-function'
warnings on clang 3.4 or later. This means we don't need to mark it
'inline', which is what we were previously using to suppress the warning
(a trick which only works with gcc, not clang).
Signed-off-by: NSeokYeon Hwang <syeon.hwang@samsung.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
[PMM: tweaked comment message a little]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

translate-all.c

@@ -276,14 +276,14 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
 }
 
 #ifdef _WIN32
-static inline void map_exec(void *addr, long size)
+static __attribute__((unused)) void map_exec(void *addr, long size)
 {
     DWORD old_protect;
     VirtualProtect(addr, size,
                    PAGE_EXECUTE_READWRITE, &old_protect);
 }
 #else
-static inline void map_exec(void *addr, long size)
+static __attribute__((unused)) void map_exec(void *addr, long size)
 {
     unsigned long start, end, page_size;