cmd/link/internal/ld: fix DWARF type DIE "go kind" bug for synthetic ptr types
The code path in linker DWARF type generation that synthesizes pointer
type DIEs needed for other synthesized types wasn't properly setting
the DW_AT_go_kind attribute for the new pointer types.
Fixes #64231.
Change-Id: I70c338d2b33ae3b93a4c6f201e5836d91d368086
Reviewed-on: https://go-review.googlesource.com/c/go/+/544315 Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>