NeedsSourcePositionsForProfiling is used to control the generation of
the line end table during parsing (see ParseInfo::CreateScript). This
is costly both for memory and performance. Turning on detailed_line_info
by default caused regressions because we always generate the line end
table.

This CL splits the two conditions apart as they aren't related.

Bug: chromium:875677
Change-Id: I71006db586e504b4cf9232081ba249f5647f5b76
Reviewed-on: https://chromium-review.googlesource.com/1181041Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55222}