Fixed a case of ARM disassembly getting an assert on a bad encoding
of a VST instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154544 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index e1d63fa..05e3ced 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -2410,6 +2410,8 @@
     case ARM::VST2b8wb_register:
     case ARM::VST2b16wb_register:
     case ARM::VST2b32wb_register:
+      if (Rm == 0xF)
+        return MCDisassembler::Fail;
       Inst.addOperand(MCOperand::CreateImm(0));
       break;
     case ARM::VST3d8_UPD: