Avoid storing Module/SemContext in non-debug global eval

[avp]

Summary:
Pull Request resolved: #2053

BCProviderFromSrc is typically used in debug and dev scenarios, but some users also invoke it via production global eval.

We don't want to keep the M and semCtx alive for these cases, because the debugger doesn't exist and there's no lazy compilation to require this data. It just bloats memory usage and is never accessed.

Note that this won't reduce memory usage for large eval strings when smart compilation is enabled, because that still uses lazy compilation. To fix it in those scenarios, the user must also pass CompilationMode::ForceEagerCompilation to RuntimeConfig.

Ran a simple eval benchmark:

(function() {
  globalThis.arr = [];
  var N = 10_000;
  for (var i = 0; i < N; ++i) {
    var f = (1,eval)(`
    function foo_${i}() {}
    `);
    globalThis.arr.push(f);
  }

  // loop while we check the memory
  gc();
  for (;;) {}
})();

This diff takes the total memory usage from 950 MB to 140 MB (measured with Activity Monitor on M4 Max MacBook).

Reviewed By: lavenzg

Differential Revision: D108782017

fbshipit-source-id: 526f1ab1e3c4347d312270f11c6ba3ca5813fb4a