This reverts commit 15fe64c0.

Reason for revert: Need to revert:
https://chromium-review.googlesource.com/c/613880

Original change's description:
> [wasm] Handle non-asm-js case in WasmCompiledModule::GetAsmJsSourcePosition.
> 
> This hides more implementation details and simplifies callers.
> 
> R=​ahaas@chromium.org
> 
> Bug: 
> Change-Id: I4809611c55b810a3b0674713e12f3f17401e6c9c
> Reviewed-on: https://chromium-review.googlesource.com/620713
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Commit-Queue: Ben Titzer <titzer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47434}

TBR=titzer@chromium.org,ahaas@chromium.org

Change-Id: I291d5ffeb52cb4731d87486f56e5c890e91e6cec
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/622588Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47449}