[flang] Address review comments.
authorTim Keith <tkeith@nvidia.com>
Fri, 6 Apr 2018 17:46:30 +0000 (10:46 -0700)
committerGitHub <noreply@github.com>
Fri, 6 Apr 2018 21:09:49 +0000 (14:09 -0700)
commit0083eb525906e40f78037d74a526d1922680d41f
treea3886f91cb2af41b49246d718c2347e80afc2e37
parent807886fb81f36253411145ee3700fecb8c190924
[flang] Address review comments.

Maintain stack of ImplicitRules in parallel with the scope stack.
I doesn't have to live as long as the scopes.

Allow for '_', '$', and '@' in ImplicitRules if they come through from
the parser.

Original-commit: flang-compiler/f18@b70e9fc9564a2cae40fce71ee7c035a502bdb7f3
Reviewed-on: https://github.com/flang-compiler/f18/pull/41
flang/lib/semantics/resolve-names.cc