Wasm frames are special in that they have a non-integer script id
in inspector. The way we treat script ids currently is a bit of a mess -
our runtime functions expected integer IDs while inspector has string
IDs (which contain integers, except for Wasm frames). This will need to
be cleaned up once more Wasm tests are added.

The meaning of line/column numbers has also changed; the old JS debug
API encoded the function index and byte offset into line/column numbers,
while inspector-based API actually translates into lines/columns in the
disassembly.

BUG=v8:5530

Review-Url: https://codereview.chromium.org/2515133003
Cr-Commit-Position: refs/heads/master@{#41182}