Convert assert(0) to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149967 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 60fa9a7..73ae6ad 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -267,7 +267,7 @@
     
     // Otherwise, rebuild a modified type.
     switch (Ty->getTypeID()) {
-    default: assert(0 && "unknown derived type to remap");
+    default: llvm_unreachable("unknown derived type to remap");
     case Type::ArrayTyID:
       return *Entry = ArrayType::get(ElementTypes[0],
                                      cast<ArrayType>(Ty)->getNumElements());