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/disassembler/disassembler_mips.cc b/disassembler/disassembler_mips.cc
index 769263e..3448878 100644
--- a/disassembler/disassembler_mips.cc
+++ b/disassembler/disassembler_mips.cc
@@ -504,9 +504,9 @@
               if (rs == 17) {
                 args << "  ; ";
                 if (is64bit_) {
-                  Thread::DumpThreadOffset<8>(args, offset);
+                  Thread::DumpThreadOffset<kMips64PointerSize>(args, offset);
                 } else {
-                  Thread::DumpThreadOffset<4>(args, offset);
+                  Thread::DumpThreadOffset<kMipsPointerSize>(args, offset);
                 }
               }
             }