... between the `OpFunction` and `OpLabel`.

It is legal to have `OpLine`s between here, which we were incorrectly warning about.
The `OpenCL.Debug.Info` opcodes can also sit here, which are numerous. Just silence the warning, we're only scanning forward for the `OpLabel` here.

Bug: b/148401179
Change-Id: Ia9b8b024a1a15bbf431abec8f8ec47e2b735ed1b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/42328Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>