Auto merge of #34614 - cynicaldevil:build-time, r=alexcrichton
Auto merge of #34614 - cynicaldevil:build-time, r=alexcrichton

Build: Shows total time taken to build the compiler

Fixes #34600
Prints the total time taken to build rustc by executing `src/bootstrap/bootstrap.py`; also includes time taken to download `stage0` compiler and deps.

r? @alexcrichton

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