Select LLVM OpenMP as the default backend

debian/changelog

@@ -8,6 +8,7 @@ llvm-toolchain-snapshot (1:3.8~svn246420-1) UNRELEASED; urgency=medium
     - lit-lang.diff
     - locale-issue-ld.diff
   * Also generate liblldb-3.8-dbg
+  * Select LLVM OpenMP as the default backend
 
   [ Gianfranco Costamagna ]
   * d/control: Add more conflicting packages (python-clang and python-lldb)

debian/rules

@@ -214,6 +214,7 @@ override_dh_auto_configure: preconfigure
 		--with-bug-report-url=http://bugs.debian.org/ \
 		--enable-shared \
 	        --disable-bindings \
+		--with-clang-default-openmp-runtime=libomp \
 		$(CONFIGURE_EXTRA) \
 		CLANG_VENDOR=$(VENDOR) || { cat config.log tools/polly/config.log; exit 1; }; \
 	else \