[ddc] Fix import names in ddb script
[ddc] Fix import names in ddb script

Some benchmarks are located in directories named with characters
that are invalid in js identifiers. To generate bootstrapping that
loads these modules import the module builder and use the same
naming method that ddc uses.

These names are directly tied to the version of ddc that produces
them. This solidifies the fact that we really can't rely on using
the ddb script to run ddc from a different commit/build.

Change-Id: I92349d70134886de63686d88f5eab9da12b4021f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/156820
Reviewed-by: Mark Zhou <654f5fe0c4ca6c799b0e735dcf3fc1c389f35bf9@google.com>
Commit-Queue: Nicholas Shahan <03847abd2d8aadfe859ecb98095a31f9f515dc47@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk