Cherry-pick Clang upstream r199830 - Handle va_arg on struct types for the le32 target (PNaCl and E…

Cherry-pick Clang upstream r199830 - Handle va_arg on struct types for the le32 target (PNaCl and Emscripten)

Author: mseaborn
Date: Wed Jan 22 14:11:01 2014
New Revision: 199830

URL: http://llvm.org/viewvc/llvm-project?rev=199830&view=rev
Log:
Handle va_arg on struct types for the le32 target (PNaCl and Emscripten)

PNaCl and Emscripten can both handle va_arg IR instructions with
struct type.

Also add a test to cover generating a va_arg IR instruction from
va_arg in C on le32 (as already handled by VisitVAArgExpr() in
CGExprScalar.cpp), which was not covered by a test before.

(This fixes https://code.google.com/p/nativeclient/issues/detail?id=2381)

Differential Revision: http://llvm-reviews.chandlerc.com/D2539

R=mseaborn@chromium.org, dschuff@chromium.org, jvoung@chromium.org
TEST= ninja clang-check
BUG= https://code.google.com/p/nativeclient/issues/detail?id=2381

Committed: c9e1197

[JF, 2014-03-06 03:59:02]

This patch was asked to be cherry-picked on Twitter
(https://twitter.com/take_cheeze/status/440559473938423808). It should only go
in once the LLVM 3.4 merge is truly in and stable (it's still making its way to
mainline Chrome, blocked on non-NaCl issues).

[JF, 2014-03-06 18:00:32]

LLVM 3.4 is now in Chrome (as of https://codereview.chromium.org/187673006/), so
this cherry-pick can go in too.

[Mark Seaborn, 2014-03-06 18:09:52]

LGTM

[JF, 2014-03-06 18:22:01]

The CQ bit was checked by jfb@chromium.org

[JF, 2014-03-06 20:42:05]

Committed patchset #1 manually as rc9e1197 (presubmit successful).