[DWARFv5] llvm-mc support for new unit header.

This is for running the assembler with -g (to emit DWARF describing
the assembler source).

Differential Revision: http://reviews.llvm.org/D30475

llvm-svn: 296541
diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index 497fb19..87efac2 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -516,7 +516,7 @@
   Ctx.setGenDwarfForAssembly(GenDwarfForAssembly);
   // Default to 4 for dwarf version.
   unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4;
-  if (DwarfVersion < 2 || DwarfVersion > 4) {
+  if (DwarfVersion < 2 || DwarfVersion > 5) {
     errs() << ProgName << ": Dwarf version " << DwarfVersion
            << " is not supported." << '\n';
     return 1;