devel/go-tools: update to 0.38.0

Selected upstream changes:

• go/ssa: support new(expr)
• cmd/stringer: document option -trimprefix
• cmd/stringer: fix bounds checking for integer types spanning full range
• cmd/eg: build tags support
• go.mod: update golang.org/x dependencies

Changelog: https://github.com/golang/tools/compare/v0.37.0...v0.38.0