backend_optimization_level query is also provided for extern crates, but only used for LOCAL_CRATE

[bjorn3]

rust/src/librustc_codegen_ssa/base.rs

Lines 857 to 858 in e82734e

	pub fn provide_both(providers: &mut Providers<'_>) {
	providers.backend_optimization_level = |tcx, cratenum| {

@rustbot modify labels: +A-codegen +C-cleanup