[Interpreter] Enable assignments in expressions.

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index 130d54b692dfb1b9c9f11d043a3ecdc78903a615..04980193a993c26bb13589b5b3e031bf639545a0 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -97,6 +97,9 @@ class BytecodeArrayBuilder {
   BytecodeArrayBuilder& LoadAccumulatorWithRegister(Register reg);
   BytecodeArrayBuilder& StoreAccumulatorInRegister(Register reg);
 
+  // Register-register transfer.
+  BytecodeArrayBuilder& MoveRegister(Register from, Register to);
+
   // Named load property.
   BytecodeArrayBuilder& LoadNamedProperty(Register object, size_t name_index,
                                           int feedback_slot,