[interpreter] Introduce fused bytecodes for common sequences.

test/unittests/interpreter/bytecode-array-builder-unittest.cc

Index: test/unittests/interpreter/bytecode-array-builder-unittest.cc
diff --git a/test/unittests/interpreter/bytecode-array-builder-unittest.cc b/test/unittests/interpreter/bytecode-array-builder-unittest.cc
index 09e4a32be1ddc5da34ccd81a4c4234b16dce8870..487c02046720a6e8bdceabcc051dbce20f0373e1 100644
--- a/test/unittests/interpreter/bytecode-array-builder-unittest.cc
+++ b/test/unittests/interpreter/bytecode-array-builder-unittest.cc
@@ -47,7 +47,7 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
       .LoadLiteral(factory->NewStringFromStaticChars("A constant"))
       .StoreAccumulatorInRegister(reg)
       .LoadUndefined()
-      .StoreAccumulatorInRegister(reg)
+      .Debugger()  // Prevent peephole optimization LdaNull, Star -> LdrNull.
       .LoadNull()
       .StoreAccumulatorInRegister(reg)
       .LoadTheHole()
@@ -346,6 +346,13 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
   // Insert entry for nop bytecode as this often gets optimized out.
   scorecard[Bytecodes::ToByte(Bytecode::kNop)] = 1;
 
+  // Insert entries for bytecodes only emiited by peephole optimizer.
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrNamedProperty)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrKeyedProperty)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrGlobal)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrContextSlot)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrUndefined)] = 1;
+
   // Check return occurs at the end and only once in the BytecodeArray.
   CHECK_EQ(final_bytecode, Bytecode::kReturn);
   CHECK_EQ(scorecard[Bytecodes::ToByte(final_bytecode)], 1);