arm64, jump label: detect %c support for ARM64

As commit a9468f3 "ARM: 7333/2: jump label: detect %c
support for ARM", this patch detects the same thing for ARM64
because some ARM64 GCC versions have the same issue.

Some versions of ARM64 GCC which do support asm goto, do not
support the %c specifier. Since we need the %c to support jump
labels on ARM64, detect that too in the asm goto detection script
to avoid build errors with these versions.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

scripts/gcc-goto.sh

@@ -5,7 +5,7 @@
 cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y"
 int main(void)
 {
-#ifdef __arm__
+#if defined(__arm__) || defined(__aarch64__)
 	/*
 	 * Not related to asm goto, but used by jump label
 	 * and broken on some ARM GCC versions (see GCC Bug 48637).