[Flags] Add flag for WebAssembly lazy compilation

Lazy compilation might become one candidate configuration for Liftoff on
mobile. Hence we add the flag now so it will be available in the next
beta release for finching.

[email protected], [email protected]

Bug: 1040030, 1040061
Change-Id: Icb86a4d3c075afc111978f6797634aabd5b98020
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2002568
Reviewed-by: Ross McIlroy <[email protected]>
Reviewed-by: Jochen Eisinger <[email protected]>
Commit-Queue: Clemens Backes <[email protected]>
Cr-Commit-Position: refs/heads/master@{#733294}
8 files changed