[interpreter] Introduce bytecode generation pipeline.

test/cctest/interpreter/bytecode_expectations/ForIn.golden

 #
 # Autogenerated by generate-bytecode-expectations.
 #
 
 ---
 pool type: mixed
 execute: yes
 wrap: yes
 
 ---
@@ skipping 47 matching lines @@
 handlers: [
 ]
 
 ---
 snippet: "
   var x = 'potatoes';
   for (var p in x) { return p; }
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 45
+bytecode array length: 47
 bytecodes: [
   B(StackCheck),
   B(LdaConstant), U8(0),
   B(Star), R(1),
-  B(JumpIfUndefined), U8(38),
-  B(JumpIfNull), U8(36),
+  B(Nop),
+  B(JumpIfUndefined), U8(39),
+  B(JumpIfNull), U8(37),
   B(ToObject),
   B(Star), R(3),
   B(ForInPrepare), R(4),
   B(LdaZero),
   B(Star), R(7),
   B(ForInDone), R(7), R(6),
-  B(JumpIfTrue), U8(23),
+  B(JumpIfTrue), U8(24),
   B(ForInNext), R(3), R(7), R(4), U8(1),
-  B(JumpIfUndefined), U8(10),
+  B(JumpIfUndefined), U8(11),
   B(Star), R(0),
   B(StackCheck),
   B(Ldar), R(0),
   B(Star), R(2),
+  B(Nop),
   B(Return),
   B(ForInStep), R(7),
   B(Star), R(7),
-  B(Jump), U8(-24),
+  B(Jump), U8(-25),
   B(LdaUndefined),
   B(Return),
 ]
 constant pool: [
   InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE,
 ]
 handlers: [
 ]
 
 ---
@@ skipping 148 matching lines @@
   B(LdaUndefined),
   B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::FIXED_ARRAY_TYPE,
 ]
 handlers: [
 ]