fdo#82430: configure: MSVC build: avoid using SSE2 instructions

MSVC 2012 for x86 defaults to -arch:SSE2; binaries do not run on any AMD
32-bit CPU, neither on Intel Pentium III.

http://msdn.microsoft.com/en-us/library/vstudio/7t5yh4fd%28v=vs.110%29.aspx

(cherry picked from commit 8bd6bf93b7711a7ac7c5cbd7c3bb980481570ebd)

fdo#82430: MSVC 2010 refuses both -clr and -arch in the same command
(cherry picked from commit 36ce22f41a754fa405804434899a08a23081e721)

fdo#82430: gcc-wrappers: don't stop if REAL_CXX_FLAGS is empty
Hopefully should fix MSVC 2010 build...
(cherry picked from commit a18ff3d5c75c2b468c48bd19439dee0689d24d67)

Change-Id: Ie8253137db2699f2a7fa69c4ac4e7ded90931e3e
Reviewed-on: https://gerrit.libreoffice.org/10925
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>
Tested-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>