Now JS::CompileForNonSyntacticScope is just a wrapper for JS::Compile's underlying-impl with options.setNonSyntacticScope(true).

https://searchfox.org/mozilla-central/rev/b2716c233e9b4398fc5923cbe150e7f83c7c6c5b/js/src/vm/CompilationAndEvaluation.cpp#113-127

JSScript* JS::CompileForNonSyntacticScope(
    JSContext* cx, const ReadOnlyCompileOptions& optionsArg,
    SourceText<char16_t>& srcBuf) {
  CompileOptions options(cx, optionsArg);
  options.setNonSyntacticScope(true);
  return CompileSourceBuffer(cx, options, srcBuf);
}

JSScript* JS::CompileForNonSyntacticScope(
    JSContext* cx, const ReadOnlyCompileOptions& optionsArg,
    SourceText<Utf8Unit>& srcBuf) {
  CompileOptions options(cx, optionsArg);
  options.setNonSyntacticScope(true);
  return CompileSourceBuffer(cx, options, srcBuf);
}

Having separate API for this isn't good when we want to introduce stencil-related compilation API, given it doubles the variants.
There's no consumer that depends on options not being modified (except testcase),
so all callsites can be replaced with options.setNonSyntacticScope(true) + JS::Compile.

This will simplify bug 1660940 (JS::CompileToStencil), and also bug 1662273 (if we go with composite API for "compile + start XDR encode").

https://treeherder.mozilla.org/#/jobs?repo=try&revision=ca50e5216287caafe24556c8de97072734e1772c&group_state=expanded

https://hg.mozilla.org/mozilla-central/rev/7e4eab0c0430