cmd/ld: don't generate DW_AT_type attr for unsafe.Pointer to match gcc behavior
gcc generates only attr DW_AT_byte_size for DW_TAG_pointer_type of "void *",
but we used to also generate DW_AT_type pointing to imaginary unspecified
type "void", which confuses some gdb.
This change makes old Apple gdb 6.x (specifically, Apple version gdb-1515)
accepts our binary without issue like this:
(gdb) b 'main.main'
Die: DW_TAG_unspecified_type (abbrev = 10, offset = 47079)
has children: FALSE
attributes:
DW_AT_name (DW_FORM_string) string: "void"
Dwarf Error: Cannot find type of die [in module /Users/minux/go/go2.hg/bin/go]
Special thanks to Russ Cox for pointing out the problem in comment #6 of
CL
7891044.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/
7744051