[interpreter] Bytecode register optimizer.

test/cctest/interpreter/bytecode_expectations/Delete.golden

Index: test/cctest/interpreter/bytecode_expectations/Delete.golden
diff --git a/test/cctest/interpreter/bytecode_expectations/Delete.golden b/test/cctest/interpreter/bytecode_expectations/Delete.golden
index c214e9a50fe994e3adce9e16f73fb4991c135888..d1ad283394eed0ca238050dd3567d0ed8e4b083e 100644
--- a/test/cctest/interpreter/bytecode_expectations/Delete.golden
+++ b/test/cctest/interpreter/bytecode_expectations/Delete.golden
@@ -13,15 +13,14 @@ snippet: "
 "
 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: [
@@ -37,15 +36,14 @@ snippet: "
 "
 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: [
@@ -61,15 +59,14 @@ snippet: "
 "
 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: [
@@ -106,7 +103,7 @@ snippet: "
 "
 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),
@@ -115,7 +112,8 @@ bytecodes: [
                 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),