all: format code according to Go 1.19 rules

Go 1.19 started reformatting code in a way that makes it more obvious
how it will be rendered on pkg.go.dev. It gets it almost right, but not
entirely. Therefore, I had to modify some of the comments so that they
are formatted correctly.

src/reflect/sidetables.go

@@ -7,6 +7,7 @@ import (
 // This stores a varint for each named type. Named types are identified by their
 // name instead of by their type. The named types stored in this struct are
 // non-basic types: pointer, struct, and channel.
+//
 //go:extern reflect.namedNonBasicTypesSidetable
 var namedNonBasicTypesSidetable uintptr