fix: type sizing when cross-compiling (32-bit)

[gh2o]

golangci-lint should respect GOARCH when performing typechecking.

For example, the code below fails to build with GOARCH=arm, but succeeds with GOARCH=amd64:

// -uintptr(x-y) creates a static assertion of x==y
const _ = -uintptr(unsafe.Sizeof((*byte)(nil)) - 8)

golangci-lint currently does not respect GOARCH for typechecking because it does not set types.Config.Sizes, which tells the typecheck package how to determine the size of machine-specific types (like pointers and uintptr). By default, if types.Config.Sizes is nil, SizesFor("gc", "amd64") is used by default. This will notably break typechecking for 32-bit platforms.

This PR sets types.Config.Sizes from build.Default, which is set by the GOARCH environment variable.

[boring-cyborg]

Hey, thank you for opening your first Pull Request !

[CLAassistant]

All committers have signed the CLA.

[ldez]

LGTM