[ddc] Adding a header comment to DDC-compiled JS.
Displays platform compilation information, module name, and some flags.
Example output:
// Generated by DDC, the Dart Development Compiler (to JavaScript).
// Version: 2.19.0-edge.4d13ff534d0c078ce1140cee1f7f2e112b9df96b (be) (Thu Jul 21 02:51:32 2022 +0000) on "macos_arm64"
// Module: hello_world
// Flags: canary, soundNullSafety(false), enableAsserts(true)
// Experiments: someExperiment
Change-Id: I5966b9653e17dd5ccd897135f8264598dff52ea7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253605
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Mark Zhou <markzipan@google.com>
Mark Zhou
e3a91f01d3