There are two issues with erasing null-restricted types: * not all the code paths in `Types::erasure` drop null restrictions * for some types like `String`, `Types::erasure` treats erasure as a no-op
------------- Commit messages: - Initial push Changes: https://git.openjdk.org/valhalla/pull/1870/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1870&range=00 Stats: 4 lines in 1 file changed: 2 ins; 0 del; 2 mod Patch: https://git.openjdk.org/valhalla/pull/1870.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1870/head:pull/1870 PR: https://git.openjdk.org/valhalla/pull/1870
