Use cast<T> instead of dyn_cast<T>.

llvm-svn: 205403
diff --git a/lld/lib/Core/Resolver.cpp b/lld/lib/Core/Resolver.cpp
index f7330f6..54b9e8e 100644
--- a/lld/lib/Core/Resolver.cpp
+++ b/lld/lib/Core/Resolver.cpp
@@ -137,7 +137,7 @@
 }
 
 void Resolver::handleArchiveFile(const File &file) {
-  const ArchiveLibraryFile *archiveFile = dyn_cast<ArchiveLibraryFile>(&file);
+  const ArchiveLibraryFile *archiveFile = cast<ArchiveLibraryFile>(&file);
   auto callback = [&](StringRef undefName, bool dataSymbolOnly) {
     if (const File *member = archiveFile->find(undefName, dataSymbolOnly)) {
       member->setOrdinal(_context.getNextOrdinalAndIncrement());
@@ -151,7 +151,7 @@
 
 void Resolver::handleSharedLibrary(const File &file) {
   // Add all the atoms from the shared library
-  const SharedLibraryFile *sharedLibrary = dyn_cast<SharedLibraryFile>(&file);
+  const SharedLibraryFile *sharedLibrary = cast<SharedLibraryFile>(&file);
   handleFile(*sharedLibrary);
 
   auto callback = [&](StringRef undefName, bool dataSymbolOnly) {