JitArm64: Fix MSVC warning '~': zero extending 'u32' to 'u64'

While the third parameter of ANDI2R is u64, the upper half of
it does not get read if we're emitting a 32-bit instruction
(which we are doing here).

Source/Core/Core/PowerPC/JitArm64/JitArm64_SystemRegisters.cpp

@@ -714,7 +714,8 @@ void JitArm64::mcrfs(UGeckoInstruction inst)
 
   if (mask != 0)
   {
-    ANDI2R(WA, WA, ~mask);
+    const u32 inverted_mask = ~mask;
+    ANDI2R(WA, WA, inverted_mask);
     STR(IndexType::Unsigned, WA, PPC_REG, PPCSTATE_OFF(fpscr));
   }