go/types, types2: error reported for valid shifts

[griesemer]

Extracted from test/shift1.go which is currently not passing (excluded) in 1.18:

package p

func _(x int, s uint) {
	x = (1. << s) << (1 << s)
	x = (1. << s) << (1. << s)
}

reports

x.go:4:6: invalid operation: shifted operand (1. << s) (untyped float value) must be integer
x.go:5:6: invalid operation: shifted operand (1. << s) (untyped float value) must be integer

These should probably be valid. Regression.

cc @findleyr

[gopherbot]

Change https://go.dev/cl/398316 mentions this issue: types2: don't report an error for certain valid shifts

[griesemer]

Didn't get to this. Moving to 1.20.

[gopherbot]

This issue is currently labeled as early-in-cycle for Go 1.20.
That time is now, so a friendly reminder to look at it again.

[gopherbot]

Change https://go.dev/cl/426661 mentions this issue: go/types: test shifts that are disabled in shared test file

[gopherbot]

This issue is currently labeled as early-in-cycle for Go 1.21.
That time is now, so a friendly reminder to look at it again.