Rollup merge of #81369 - tgnottingham:codegen-to-llvm-ir-wall-time, r=lcnr
Rollup merge of #81369 - tgnottingham:codegen-to-llvm-ir-wall-time, r=lcnr

rustc_codegen_ssa: use wall time for codegen_to_LLVM_IR time-passes entry

Use elapsed wall time spent on codegen_to_LLVM_IR for all CGUs as a
whole, rather than the sum for each CGU (the distinction matters for
parallel builds, where some CGUs are processed in parallel).

aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust