cmd/cgo: check function argument/return types for bad C pointer types
We need to determine whether arguments to and return values from C
functions are "bad" typedef'd pointer types which need to be uintptr
on the Go side.
The type of those arguments are not specified explicitly. As a result,
we never look through the C declarations for the GetTypeID functions
associated with that type, and never realize that they are bad.
However, in another function in the same package there might be an
explicit reference. Then we end up with the declaration being uintptr
in one file and *struct{...} in another file. Badness ensues.
Fix this by doing a 2-pass algorithm. In the first pass, we run as
normal, but record all the argument and result types we see. In the
second pass, we include those argument types also when reading the C
types.
Fixes #24161
Change-Id: I8d727e73a2fbc88cb9d9899f8719ae405f59f753
Reviewed-on: https://go-review.googlesource.com/122575
Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>