fix some casts that I improperly refactored, patch by Artur Pietrek!

llvm-svn: 75894
diff --git a/llvm/lib/Target/MSIL/MSILWriter.cpp b/llvm/lib/Target/MSIL/MSILWriter.cpp
index 8bd3c7b..dbfcdb7 100644
--- a/llvm/lib/Target/MSIL/MSILWriter.cpp
+++ b/llvm/lib/Target/MSIL/MSILWriter.cpp
@@ -235,7 +235,7 @@
 
 std::string MSILWriter::getValueName(const Value* V) {
   std::string Name;
-  if (const GlobalValue *GV = cast<GlobalValue>(V))
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
     Name = Mang->getMangledName(GV);
   else {
     unsigned &No = AnonValueNumbers[V];
@@ -262,7 +262,7 @@
 
 std::string MSILWriter::getLabelName(const Value* V) {
   std::string Name;
-  if (const GlobalValue *GV = cast<GlobalValue>(V))
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
     Name = Mang->getMangledName(GV);
   else {
     unsigned &No = AnonValueNumbers[V];