Add fixup for Thumb1 BL/BLX instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121072 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 5492887..4daab49 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -1546,6 +1546,7 @@
     case ARM::fixup_arm_ldst_pcrel_12:
     case ARM::fixup_arm_pcrel_10:
     case ARM::fixup_arm_adr_pcrel_12:
+    case ARM::fixup_arm_thumb_bl:
       assert(0 && "Unimplemented"); break;
     case ARM::fixup_arm_branch:
       return ELF::R_ARM_CALL; break;