MC/Mach-O: Return to reporting errors if we see unexpected fixup kinds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122409 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp
index 2cfd10b..167cda7 100644
--- a/lib/MC/MachObjectWriter.cpp
+++ b/lib/MC/MachObjectWriter.cpp
@@ -34,17 +34,14 @@
 // FIXME: this has been copied from (or to) X86AsmBackend.cpp
 static unsigned getFixupKindLog2Size(unsigned Kind) {
   switch (Kind) {
-  // FIXME: Until ARM has it's own relocation stuff spun off, it comes
-  // through here and we don't want it to puke all over. Any reasonable
-  // values will only come when ARM relocation support gets added, at which
-  // point this will be X86 only again and the llvm_unreachable can be
-  // re-enabled.
-  default: return 0;// llvm_unreachable("invalid fixup kind!");
+  default:
+    llvm_unreachable("invalid fixup kind!");
   case FK_PCRel_1:
   case FK_Data_1: return 0;
   case FK_PCRel_2:
   case FK_Data_2: return 1;
   case FK_PCRel_4:
+    // FIXME: Remove these!!!
   case X86::reloc_riprel_4byte:
   case X86::reloc_riprel_4byte_movq_load:
   case X86::reloc_signed_4byte: