[arm64] Optimize fcmp when lhs operand is #0.0

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index e9b3a9949a28cf00ea484b84708e5e8131d574ab..d4fe21505c4fd7971c1ea97580680cf698a58819 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -1026,6 +1026,9 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
     case kNotOverflow:
       __ j(no_overflow, tlabel);
       break;
+    default:
+      UNREACHABLE();
+      break;
   }
   // Add a jump if not falling through to the next block.
   if (!branch->fallthru) __ jmp(flabel);
@@ -1096,6 +1099,9 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
     case kNotOverflow:
       cc = no_overflow;
       break;
+    default:
+      UNREACHABLE();
+      break;
   }
   __ bind(&check);
   if (reg.is_byte_register()) {