Fix build failure on MSVC compilers.

llvm-svn: 232368
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index e37cd55..3554715 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -243,9 +243,8 @@
       0, // length of DW_LNS_set_epilogue_begin
       1  // DW_LNS_set_isa
   };
-  static_assert(array_lengthof(StandardOpcodeLengths) ==
-                    (DWARF2_LINE_OPCODE_BASE - 1),
-                "");
+  assert(array_lengthof(StandardOpcodeLengths) ==
+         (DWARF2_LINE_OPCODE_BASE - 1));
   return Emit(MCOS, StandardOpcodeLengths);
 }