pkg go/doc/comment, type DocLink struct, Recv string #51082
pkg go/doc/comment, type DocLink struct, Text []Text #51082
pkg go/doc/comment, type Heading struct #51082
pkg go/doc/comment, type Heading struct, Text []Text #51082
pkg go/doc/comment, type Italic string #51082
pkg go/doc/comment, type Link struct #51082
pkg go/doc/comment, type Link struct, Auto bool #51082
pkg go/doc/comment, type Link struct, Text []Text #51082

are also treated as invalid.
(Older toolchains ignore `//go:debug` directives entirely.)

The defaults that will be compiled into a main package
are reported by the command:

{{raw `
	go list -f '{{.DefaultGODEBUG}}' my/main/package
`}}

Only differences from the base Go toolchain defaults are reported.

When testing a package, `//go:debug` lines in the `*_test.go`

# CL 122960043 encoding/xml: add InputOffset method to Decoder, Russ Cox <******@****.***>
pkg encoding/xml, method (*Decoder) InputOffset() int64

# CL 124940043 cmd/go, go/build: implement import comment checking, Russ Cox <******@****.***>
pkg go/build, const ImportComment = 4
pkg go/build, const ImportComment ImportMode
pkg go/build, type Package struct, ImportComment string