package/archlinux: don't force C++11 for the libc++ build.

It made sense back in 2013 or so, but certainly not anymore, as it breaks
some tests and causes compiler warnings in code that enables C++14
features.

package/archlinux/PKGBUILD-clang-libc++

@@ -20,7 +20,7 @@ build() {
 
         cmake .. \
             -DCMAKE_CXX_COMPILER=clang++ \
-            -DCMAKE_CXX_FLAGS="-std=c++11 -stdlib=libc++" \
+            -DCMAKE_CXX_FLAGS="-stdlib=libc++" \
             -DCMAKE_EXE_LINKER_FLAGS=-lc++abi \
             -G Ninja
     fi
@@ -72,3 +72,5 @@ package() {
     cd "$_rootdir/build-clang-libc++"
     DESTDIR="$pkgdir/" ninja install
 }
+
+# kate: hl bash