Simpler memset, avoids ICE on VS2013 Update2

Simpler memset, avoids ICE on VS2013 Update2

The previous code is causing:

FAILED: ninja -t msvc -e environment.x86 -- C:\b\build\goma/gomacc "C:\b\depot_tools\win_toolchain\vs2013_files\VC\bin\amd64_x86\cl.exe" /nologo /showIncludes /FC @obj\chrome\installer\mini_installer\mini_installer.mini_installer.obj.rsp /c ..\..\chrome\installer\mini_installer\mini_installer.cc /Foobj\chrome\installer\mini_installer\mini_installer.mini_installer.obj /Fdobj\chrome\installer\mini_installer.cc.pdb
c:\b\build\slave\win-latest-rel\build\src\chrome\installer\mini_installer\mini_installer.cc(857) : fatalerror C1001: An internal error has occurred in the compiler.
(compiler file 'f:\dd\vctools\compiler\utc\src\p2\main.c', line 228)
 To work around this problem, try simplifying or changing the program near the locations listed above.
Please choose the Technical Support command on the Visual C++
 Help menu, or open the Technical Support help file for more information
INTERNAL COMPILER ERROR in 'C:\b\depot_tools\win_toolchain\vs2013_files\VC\bin\amd64_x86\cl.exe'
    Please choose the Technical Support command on the Visual C++
    Help menu, or open the Technical Support help file for more information

after Update 2. The CRT's implementation looks like the simple char
loop, so simplify here too.

In practice, I think this will only rarely get used, as the compiler
is allowed to "know" what memset does and replace it with an optimized
version.

There's an upstream bug filed here: https://connect.microsoft.com/VisualStudio/feedback/details/878340/ice-on-memset-implementation-at-o2

R=grt@chromium.org
BUG=372451
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271919

[grt (UTC plus 2), 2014-05-20 23:04:04]

https://codereview.chromium.org/294943005/diff/1/chrome/installer/mini_instal...
File chrome/installer/mini_installer/mini_installer.cc (right):

https://codereview.chromium.org/294943005/diff/1/chrome/installer/mini_instal...
chrome/installer/mini_installer/mini_installer.cc:839:
*reinterpret_cast<char*>(dest) = static_cast<char>(val);
val -> c?

[scottmg, 2014-05-20 23:55:57]

https://codereview.chromium.org/294943005/diff/1/chrome/installer/mini_instal...
File chrome/installer/mini_installer/mini_installer.cc (right):

https://codereview.chromium.org/294943005/diff/1/chrome/installer/mini_instal...
chrome/installer/mini_installer/mini_installer.cc:839:
*reinterpret_cast<char*>(dest) = static_cast<char>(val);
On 2014/05/20 23:04:04, grt wrote:
> val -> c?

Urgh. :( Thanks.

I also confirm that I can reproduce the ICE before the patch, and that it's
fixed after.

[grt (UTC plus 2), 2014-05-21 10:29:26]

lgtm

[commit-bot: I haz the power, 2014-05-21 10:31:47]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scottmg@chromium.org/294943005/20001

[scottmg, 2014-05-21 17:07:03]

Committed patchset #2 manually as r271919 (presubmit successful).