vim-ide-integration: clang does not always like gnu++1y that much

And gives the error:

include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace

when it's build against libstdc++.

Commit 9e6221f114 (clang does not like gnu++11
that much, use c++11 instead, 2014-09-06) added support for invoking clang for
IDE purposes even in a tree configured for gcc. Extend this in case configure
sets -std=gnu++1y for gcc as well.

Change-Id: Ib767ef8f30bd6eb9ac825a1521184041f1269d93
Reviewed-on: https://gerrit.libreoffice.org/23983
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>

bin/gbuild-to-ide

@@ -464,7 +464,10 @@ class VimIntegrationGenerator(IdeIntegrationGenerator):
             command += cxxflag
         command += ' -c '
         command += file
-        return command.replace('-std=gnu++11', '-std=c++11')
+        # Help clang when the tree is configured for gcc.
+        for gnu in ('-std=gnu++11', '-std=gnu++1y'):
+            command = command.replace(gnu, '-std=c++11')
+        return command
 
 
 class KdevelopIntegrationGenerator(IdeIntegrationGenerator):