Backport build.rs fixes to 1.x. #1736

Job	Run time
Rustfmt	5s
Check Cross-Compilation on Rust nightly on Windows (nightly)	1m 5s
Check Cross-Compilation on Rust nightly (nightly)	1m 22s
Check Cross-Compilation (stable)	44s
Check Cross-Compilation on Windows (stable)	44s
Check Cross-Compilation (beta)	41s
Check Cross-Compilation on Windows (beta)	47s
Test (stable)	15s
Test linux-raw support (ubuntu)	24s
Test on Musl (ubuntu)	26s
Test (windows-latest)	15s
Test with Rust nightly (ubuntu)	1s
Test linux-raw support (ubuntu-20.04)	24s
Test (windows-2019)	18s
Test with Rust nightly (windows)	40s
Test (macos-latest)	18s
Fuzz Targets	47s
Test (macos-12)	1s
Test (msrv)	1m 49s
Test (beta)	22s
Test (ubuntu-20.04)	16s
Test (aarch64-ubuntu)	28s
	12m 12s

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