Add hook in MCSection to decide when to use "optimized nops", for each
section kind. Previously, optimized nops were only used for MachO.
Also added tests for ELF and COFF.

llvm-svn: 115523
diff --git a/llvm/lib/MC/MCSectionCOFF.cpp b/llvm/lib/MC/MCSectionCOFF.cpp
index eb53160..0909df4 100644
--- a/llvm/lib/MC/MCSectionCOFF.cpp
+++ b/llvm/lib/MC/MCSectionCOFF.cpp
@@ -74,3 +74,7 @@
     }
   }
 }
+
+bool MCSectionCOFF::UseCodeAlign() const {
+  return getKind().isText();
+}