cmd/compile: optimize const rotates for wasm architecture
This removes the unnecessary code to check whether the shift
is within limits or not when the shift amount is a constant.
The rules hit 23034 times when building std cmd.
grep -E "Wasm.rules:(106|107|121|122|139|140)" rulelog | wc -l
23034
Reduces the size of pkg/js_wasm by 132 bytes.
Change-Id: I64a2b8faca08c3b5039d6a027d4676130d2db18d
Reviewed-on: https://go-review.googlesource.com/c/go/+/194239
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Richard Musiol <neelance@gmail.com>