better const folding for int and bool #710

Job	Run time
Lint	6m 32s
Difftest (windows-2022)	16m 48s
cargo-deny	1m 0s
Difftest (ubuntu-24.04)	9m 42s
Compiletest (windows-2022)	16m 17s
Compiletest (macOS-latest)	8m 13s
Compiletest (ubuntu-24.04)	8m 25s
Difftest (macOS-latest)	11m 31s
Test (macOS-latest)	9m 4s
Android (ubuntu-24.04, aarch64-linux-android)	8m 26s
Test (windows-2022)	14m 40s
Test (ubuntu-24.04)	8m 13s
test_success	2s
	1h 58m 53s

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