[interpreter] Bytecode register optimizer.

test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden

Index: test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
diff --git a/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden b/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
index 374a203a8dc6f7f8206ba32c14855770701fa609..cd38f5fca854954a14cdebc5e1e67ef02ab041d4 100644
--- a/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
+++ b/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
@@ -13,15 +13,15 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 16
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(1),
   /*   42 E> */ B(Star), R(0),
-  /*   45 S> */ B(Star), R(1),
-                B(LdaSmi), U8(2),
-                B(Add), R(1),
-  /*   47 E> */ B(Star), R(0),
+  /*   45 S> */ B(LdaSmi), U8(2),
+                B(Add), R(0),
+  /*   47 E> */ B(Mov), R(0), R(1),
+                B(Star), R(0),
                 B(LdaUndefined),
   /*   53 S> */ B(Return),
 ]
@@ -36,15 +36,15 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 16
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), U8(1),
   /*   42 E> */ B(Star), R(0),
-  /*   45 S> */ B(Star), R(1),
-                B(LdaSmi), U8(2),
-                B(Div), R(1),
-  /*   47 E> */ B(Star), R(0),
+  /*   45 S> */ B(LdaSmi), U8(2),
+                B(Div), R(0),
+  /*   47 E> */ B(Mov), R(0), R(1),
+                B(Star), R(0),
                 B(LdaUndefined),
   /*   53 S> */ B(Return),
 ]
@@ -59,18 +59,17 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 27
+bytecode array length: 25
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
   /*   42 E> */ B(Star), R(0),
-  /*   54 S> */ B(Star), R(1),
-                B(LoadIC), R(1), U8(1), U8(1),
+  /*   54 S> */ B(LoadIC), R(0), U8(1), U8(1),
                 B(Star), R(2),
                 B(LdaSmi), U8(2),
                 B(Mul), R(2),
-  /*   61 E> */ B(StoreICSloppy), R(1), U8(1), U8(3),
+  /*   61 E> */ B(StoreICSloppy), R(0), U8(1), U8(3),
                 B(LdaUndefined),
   /*   67 S> */ B(Return),
 ]
@@ -87,20 +86,19 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 30
+bytecode array length: 28
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
   /*   42 E> */ B(Star), R(0),
-  /*   52 S> */ B(Star), R(1),
-                B(LdaSmi), U8(1),
+  /*   52 S> */ B(LdaSmi), U8(1),
                 B(Star), R(2),
-                B(KeyedLoadIC), R(1), U8(1),
+                B(KeyedLoadIC), R(0), U8(1),
                 B(Star), R(3),
                 B(LdaSmi), U8(2),
                 B(BitwiseXor), R(3),
-  /*   57 E> */ B(KeyedStoreICSloppy), R(1), R(2), U8(3),
+  /*   57 E> */ B(KeyedStoreICSloppy), R(0), R(2), U8(3),
                 B(LdaUndefined),
   /*   63 S> */ B(Return),
 ]