swift

2dd0da30 - build-script: Default --llvm-enable-index-store=0 when --sccache is set

build-script: Default --llvm-enable-index-store=0 when --sccache is set sccache can't cache compilations that emit -index-store-path side outputs: it sees the extra .o.indexstore-derived files as inputs that vary per source location and bails. With the index store left on, every translation unit misses the cache, which defeats the entire reason sccache was requested. --llvm-enable-index-store keeps its default of True. In apply_default_arguments() we force it off whenever --sccache is set, which is the only configuration where the index store is known to actively harm the build.