better const folding for int and bool #677

Job	Run time
Test (ubuntu-24.04)	8m 9s
Android (ubuntu-24.04, aarch64-linux-android)	8m 1s
Test (macOS-latest)	9m 52s
Test (windows-2022)	14m 32s
Compiletest (ubuntu-24.04)	8m 12s
Compiletest (windows-2022)	15m 52s
Compiletest (macOS-latest)	6m 33s
Difftest (ubuntu-24.04)	9m 50s
Lint	6m 50s
Difftest (windows-2022)	17m 0s
Difftest (macOS-latest)	10m 23s
cargo-deny	1m 9s
test_success	2s
	1h 56m 25s

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