cmd/compile,cmd/link: set DW_AT_decl_line for function declarations

DW_AT_decl_line provides the line number of function declarations (the
line containing the func keyword). This is the equivalent to CL 429638,
but provided via DWARF.

Note that the file of declarations (DW_AT_decl_file) is already provided
for non-inlined functions. It is omitted for inlined functions because
those DWARF subprograms may be generated outside of their source
compilation unit, where referencing the file table is difficult.

Fixes #57308.

Change-Id: I3ad12e1f366c4465c2a588297988a5825ef7efec
Reviewed-on: https://go-review.googlesource.com/c/go/+/458195
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>

0 files changed, 0 insertions, 0 deletions