BlocksRuntime: match the ABI specification for LLP64

The Blocks ABI v1 defined the `size` and `reserved` fields as `unsigned
long int` rather than `uintptr_t`.  This breaks on LLP64 hosts where
`uintptr_t` is larger than `unsigned long int`.  Make this conform to
the specification.

Signed-off-by: Kim Topley <ktopley@apple.com>

Author: compnerd

src/BlocksRuntime/Block_private.h

@@ -38,8 +38,8 @@ enum {
 
 #define BLOCK_DESCRIPTOR_1 1
 struct Block_descriptor_1 {
-    uintptr_t reserved;
-    uintptr_t size;
+    unsigned long int reserved;
+    unsigned long int size;
 };
 
 #define BLOCK_DESCRIPTOR_2 1