stage2: put use_llvm and use_stage1 into the Module cache hash
This prevents a compiler_rt built with stage2 (which is intentionally
different than when built with stage1) from being used for stage1 and
vice versa.
Fixes the regression from the previous commit.
4e85bf1185Andrew Kelley committed on 9/29/2021, 5:46:32 PMparent99961f2