gen_msvs_vcxproj.sh: Add /arch:AVX for files using AVX.

Turns on AVX when the final characters of .c and .cc file names preceding the
.c and .cc file extension contain the substrings avx or avx2. This silences
many MSVC warnings issued during compilation files that use AVX.

Change-Id: I82bda394af7a688679abab2a50dd7e10b3cb0c7a

build/make/gen_msvs_vcxproj.sh

@@ -174,6 +174,10 @@ generate_filter() {
                         Include=".\\$f"
                     # Separate file names with Condition?
                     tag_content ObjectFileName "\$(IntDir)$objf"
+                    # Check for AVX and turn it on to avoid warnings.
+                    if [[ $f =~ avx.?\.c$ ]]; then
+                        tag_content AdditionalOptions "/arch:AVX"
+                    fi
                     close_tag ClCompile
                 elif [ "$pat" == "h" ] ; then
                     tag ClInclude \