Support --incompatible_enable_cc_toolchain_resolution (#336)
Support --incompatible_enable_cc_toolchain_resolution (#336)

Resolve CcToolchainInfo as instructed at
https://docs.bazel.build/versions/master/integrating-with-rules-cc.html#accessing-the-c-toolchain

This allows rules_foreign_cc to be used with --incompatible_enable_cc_toolchain_resolution.
bazelbuild/rules_foreign_cc,bazelbuild/rules_foreign_cc,bazelbuild/rules_foreign_cc,bazelbuild/rules_foreign_cc