[stubs] Reduce number of StoreTransitionStub instances.

src/ic/mips64/handler-compiler-mips64.cc

Index: src/ic/mips64/handler-compiler-mips64.cc
diff --git a/src/ic/mips64/handler-compiler-mips64.cc b/src/ic/mips64/handler-compiler-mips64.cc
index 3b73a9b8e690d3bcfc678045181b615812649063..2190f6d63e2c6812245c6698ffa15acc96655ead 100644
--- a/src/ic/mips64/handler-compiler-mips64.cc
+++ b/src/ic/mips64/handler-compiler-mips64.cc
@@ -129,9 +129,13 @@ void PropertyHandlerCompiler::DiscardVectorAndSlot() {
   __ Daddu(sp, sp, Operand(2 * kPointerSize));
 }
 
-void PropertyHandlerCompiler::PushReturnAddress(Register tmp) { UNREACHABLE(); }
+void PropertyHandlerCompiler::PushReturnAddress(Register tmp) {
+  // No-op. Return address is in ra register.
+}
 
-void PropertyHandlerCompiler::PopReturnAddress(Register tmp) { UNREACHABLE(); }
+void PropertyHandlerCompiler::PopReturnAddress(Register tmp) {
+  // No-op. Return address is in ra register.
+}
 
 void PropertyHandlerCompiler::GenerateDictionaryNegativeLookup(
     MacroAssembler* masm, Label* miss_label, Register receiver,