[heap] Use size_t for heap and space counters.

src/x87/assembler-x87.cc

Index: src/x87/assembler-x87.cc
diff --git a/src/x87/assembler-x87.cc b/src/x87/assembler-x87.cc
index 62b662f28560e38acba73b0db7c9f4f66f1803fd..eb8dafa3b09230379a1e46caed75e62880d14da5 100644
--- a/src/x87/assembler-x87.cc
+++ b/src/x87/assembler-x87.cc
@@ -2052,8 +2052,9 @@ void Assembler::GrowBuffer() {
 
   // Some internal data structures overflow for very large buffers,
   // they must ensure that kMaximalBufferSize is not too large.
-  if ((desc.buffer_size > kMaximalBufferSize) ||
-      (desc.buffer_size > isolate()->heap()->MaxOldGenerationSize())) {
+  if (desc.buffer_size > kMaximalBufferSize ||
+      static_cast<size_t>(desc.buffer_size) >
+          isolate()->heap()->MaxOldGenerationSize()) {
     V8::FatalProcessOutOfMemory("Assembler::GrowBuffer");
   }