cmd/compile: initialize line number properly for temporaries

cmd/compile: initialize line number properly for temporaries

The expansion of structure, array, slice, and map literals
does not use the right line number in its introduced assignments
to temporaries, which leads to incorrect line number attribution
for expressions in those literals.

Inlining also incorrectly replaced the line numbers of args to
inlined functions.

This was revealed in CL 9721 because a now-avoided temporary
assignment introduced the correct line number.
I.e. before CL 9721
  "tmp_wrongline := expr"
was transformed to
  "tmp_rightline := expr; tmp_wrongline := tmp_rightline"

Also includes a repair to CL 10334 involving line numbers
where a spurious -1 remained (should have been 0, now is 0).

Fixes #11400.

Change-Id: I3a4687efe463977fa1e2c996606f4d91aaf22722
Reviewed-on: https://go-review.googlesource.com/11730
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>