Fix INVALID opcode error on labels defined for statements other than iteration statements.

Fixed test262 test cases:
 * ch12/12.6/12.6.1/S12.6.1_A4_T5
 * ch12/12.6/12.6.2/S12.6.2_A4_T5
Follow up for INVALID opcode fix

Handle labels on with statements.
Merge pull request #85 from LaszloLango/master

Fix INVALID opcode error