[Codegen] Fix if_then_else codegen

[spectrometerHBH]

• Evaluating op.if_then_else with a?b:c is potentially dangerous as it might evaluate expressions in branches without a guard of condition.

• While loop condition expression might require several var bindings generated, so we correct the while loop codegen from while (cond) to while (True)

[vinx13]

isn't short circuiting the defined behavior for ternary expression?

[spectrometerHBH]

isn't short circuiting the defined behavior for ternary expression?

When generating codes for a?b:c, there might be bindings for b or c generated ahead. These binding codes are not protected by condition a.

[ysh329]

isn't short circuiting the defined behavior for ternary expression?

When generating codes for a?b:c, there might be bindings for b or c generated ahead. These binding codes are not protected by condition a.

Hi, bohan, I recently am supporting Ternary Operator(like cond?true_branch:false_branch) in our device. I don't understand this modification. Can u explain this with a case? Thanks a lot!