internal/pkgbits: write a formal grammar for UIR primitives
This complements the grammar being developed in package noder. It
is unclear how to discuss references in their current state, as
they require knowledge of sections, elements, etc.
Perhaps the references here should refer to indices on the byte
array. This would allow a stronger separation of pkgbits and noder.
Change-Id: Ic0e5ac9c07f0a0b92d6ffd4d4e26dbe5dcf89e57
Reviewed-on: https://go-review.googlesource.com/c/go/+/671440 Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Bypass: Mark Freeman <mark@golang.org>
Auto-Submit: Mark Freeman <mark@golang.org>