This commit changes definition of "ExtensionFileSource", by changing
"code" field to being "ExtensionFileSourceCode" enum. Currently the enum
has only a single variant "IncludedInBinary". It is done in preparation
to allow embedders to decide if they want to include the source code in the
binary when snapshotting (in most cases they shouldn't do that).
In the follow up commit we'll add more variants to
"ExtensionFileSourceCode".
"include_js_files_dir!" macro was removed in favor "include_js_files!"
macro which can now accept "dir" option.
This reverts commit 10e50a1207
Alternative to #13217, IMO the tradeoffs made by #10786 aren't worth it.
It breaks abstractions (crates being self-contained, deno_core without snapshotting etc...) and causes pain points / gotchas for both embedders & devs for a relatively minimal gain in incremental build time ...
Closes #11030
