Fix the x86-64 int64_t/uint64_t.

This now matches aarch64, which was already correct.

Bug: 12213562
Change-Id: I5da19f0af98347992fea2a62938472f86427740f
diff --git a/libc/arch-x86_64/include/machine/_types.h b/libc/arch-x86_64/include/machine/_types.h
index bf4b957..234e652 100644
--- a/libc/arch-x86_64/include/machine/_types.h
+++ b/libc/arch-x86_64/include/machine/_types.h
@@ -62,10 +62,8 @@
 typedef	unsigned short		__uint16_t;
 typedef	int			__int32_t;
 typedef	unsigned int		__uint32_t;
-/* LONGLONG */
-typedef	long long		__int64_t;
-/* LONGLONG */
-typedef	unsigned long long	__uint64_t;
+typedef	long                    __int64_t;
+typedef	unsigned long           __uint64_t;
 
 /* 7.18.1.2 Minimum-width integer types */
 typedef	__int8_t		__int_least8_t;