ART: Convert pointer size to enum

Move away from size_t to dedicated enum (class).

Bug: 30373134
Bug: 30419309
Test: m test-art-host
Change-Id: Id453c330f1065012e7d4f9fc24ac477cc9bb9269
diff --git a/compiler/jni/quick/mips/calling_convention_mips.h b/compiler/jni/quick/mips/calling_convention_mips.h
index 5c128b0..e95a738 100644
--- a/compiler/jni/quick/mips/calling_convention_mips.h
+++ b/compiler/jni/quick/mips/calling_convention_mips.h
@@ -17,17 +17,23 @@
 #ifndef ART_COMPILER_JNI_QUICK_MIPS_CALLING_CONVENTION_MIPS_H_
 #define ART_COMPILER_JNI_QUICK_MIPS_CALLING_CONVENTION_MIPS_H_
 
+#include "base/enums.h"
 #include "jni/quick/calling_convention.h"
 
 namespace art {
 namespace mips {
 
 constexpr size_t kFramePointerSize = 4;
+static_assert(kFramePointerSize == static_cast<size_t>(PointerSize::k32),
+              "Invalid frame pointer size");
 
 class MipsManagedRuntimeCallingConvention FINAL : public ManagedRuntimeCallingConvention {
  public:
   MipsManagedRuntimeCallingConvention(bool is_static, bool is_synchronized, const char* shorty)
-      : ManagedRuntimeCallingConvention(is_static, is_synchronized, shorty, kFramePointerSize) {}
+      : ManagedRuntimeCallingConvention(is_static,
+                                        is_synchronized,
+                                        shorty,
+                                        PointerSize::k32) {}
   ~MipsManagedRuntimeCallingConvention() OVERRIDE {}
   // Calling convention
   ManagedRegister ReturnRegister() OVERRIDE;