gn: Fix stale references in Parser::AssignComments().

ParseNode::GetRange() returns a LocationRange (value, not reference),
while LocationRange::begin() returns a const Location&. Initializing a
local const Location& variable with that doesn't extend the lifetime of
the temporary.

Review-Url: https://codereview.chromium.org/2556613002
Cr-Original-Commit-Position: refs/heads/master@{#436637}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: d177088c55ef63ab7f28c34bdd124faf01adb389
1 file changed
tree: dbf9e2236a80b3e364b7634bdc6bec010a5d069e
  1. tools/