--emit KIND=PATH affects crate hash vs --emit KIND

[jsgf]

When emitting to a specific path with --emit KIND=PATH the crate hash is affected by what PATH is.
If you use --emit KIND -o PATH, or --out-dir PATH the crate hash is unaffected.

Meta

rustc --version --verbose:

rustc 1.54.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.54.0-dev
LLVM version: 12.0.1

[inquisitivecrystal]

@rustbot label +T-compiler