Convert assert(0) to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149961 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMConstantPoolValue.cpp b/lib/Target/ARM/ARMConstantPoolValue.cpp
index 78dc78f..5a830ca 100644
--- a/lib/Target/ARM/ARMConstantPoolValue.cpp
+++ b/lib/Target/ARM/ARMConstantPoolValue.cpp
@@ -62,8 +62,7 @@
 
 int ARMConstantPoolValue::getExistingMachineCPValue(MachineConstantPool *CP,
                                                     unsigned Alignment) {
-  assert(false && "Shouldn't be calling this directly!");
-  return -1;
+  llvm_unreachable("Shouldn't be calling this directly!");
 }
 
 void