[interpreter] Bytecode register optimizer.

test/cctest/interpreter/bytecode_expectations/Delete.golden

 #
 # Autogenerated by generate-bytecode-expectations.
 #
 
 ---
 pool type: mixed
 execute: yes
 wrap: yes
 
 ---
 snippet: "
   var a = {x:13, y:14}; return delete a.x;
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 14
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
                 B(Star), R(0),
-  /*   56 S> */ B(Star), R(1),
-                B(LdaConstant), U8(1),
-                B(DeletePropertySloppy), R(1),
+  /*   56 S> */ B(LdaConstant), U8(1),
+                B(DeletePropertySloppy), R(0),
   /*   75 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   'use strict'; var a = {x:13, y:14}; return delete a.x;
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 14
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   56 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
                 B(Star), R(0),
-  /*   70 S> */ B(Star), R(1),
-                B(LdaConstant), U8(1),
-                B(DeletePropertyStrict), R(1),
+  /*   70 S> */ B(LdaConstant), U8(1),
+                B(DeletePropertyStrict), R(0),
   /*   89 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   var a = {1:13, 2:14}; return delete a[2];
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 14
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
                 B(Star), R(0),
-  /*   56 S> */ B(Star), R(1),
-                B(LdaSmi), U8(2),
-                B(DeletePropertySloppy), R(1),
+  /*   56 S> */ B(LdaSmi), U8(2),
+                B(DeletePropertySloppy), R(0),
   /*   76 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
@@ skipping 16 matching lines @@
 
 ---
 snippet: "
   'use strict';
   var a = {1:10};
   (function f1() {return a;});
   return delete a[1];
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 30
 bytecodes: [
                 B(CallRuntime), U16(Runtime::kNewFunctionContext), R(closure), U8(1),
                 B(PushContext), R(0),
   /*   30 E> */ B(StackCheck),
   /*   56 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
   /*   56 E> */ B(StaContextSlot), R(context), U8(4),
   /*   64 S> */ B(CreateClosure), U8(1), U8(0),
-  /*   93 S> */ B(LdrContextSlot), R(context), U8(4), R(1),
+  /*   93 S> */ B(LdaContextSlot), R(context), U8(4),
+                B(Star), R(1),
                 B(LdaSmi), U8(1),
                 B(DeletePropertyStrict), R(1),
   /*  113 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::SHARED_FUNCTION_INFO_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   return delete 'test';
 "
 frame size: 0
 parameter count: 1
 bytecode array length: 3
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaTrue),
   /*   56 S> */ B(Return),
 ]
 constant pool: [
 ]
 handlers: [
 ]