[Interpreter] Introduce IncStub and DecStub.

test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden

 #
 # Autogenerated by generate-bytecode-expectations.
 #
 
 ---
 pool type: string
 execute: yes
 wrap: no
 test function name: f
 
 ---
 snippet: "
   var global = 1;
   function f() { return ++global; }
   f();
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
   B(StackCheck),
   B(LdaGlobal), U8(0), U8(1),
-  B(ToNumber),
   B(Inc),
   B(StaGlobalSloppy), U8(0), U8(3),
   B(Return),
 ]
 constant pool: [
   "global",
 ]
 handlers: [
 ]
 
@@ skipping 23 matching lines @@
 ]
 
 ---
 snippet: "
   unallocated = 1;
   function f() { 'use strict'; return --unallocated; }
   f();
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
   B(StackCheck),
   B(LdaGlobal), U8(0), U8(1),
-  B(ToNumber),
   B(Dec),
   B(StaGlobalStrict), U8(0), U8(3),
   B(Return),
 ]
 constant pool: [
   "unallocated",
 ]
 handlers: [
 ]
 
@@ skipping 15 matching lines @@
   B(StaGlobalSloppy), U8(0), U8(3),
   B(Ldar), R(0),
   B(Return),
 ]
 constant pool: [
   "unallocated",
 ]
 handlers: [
 ]