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/runtime/mirror/string-inl.h b/runtime/mirror/string-inl.h
index 96f2098..d3660e5 100644
--- a/runtime/mirror/string-inl.h
+++ b/runtime/mirror/string-inl.h
@@ -33,7 +33,7 @@
 namespace art {
 namespace mirror {
 
-inline uint32_t String::ClassSize(size_t pointer_size) {
+inline uint32_t String::ClassSize(PointerSize pointer_size) {
   uint32_t vtable_entries = Object::kVTableLength + 57;
   return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0, 1, 2, pointer_size);
 }