DoesBranch needs to compute the instruction if it isn't already done.
Handle the "alternate_isa" correctly.

llvm-svn: 176922
diff --git a/lldb/source/Core/Disassembler.cpp b/lldb/source/Core/Disassembler.cpp
index 8bbd8b5..3c8210b 100644
--- a/lldb/source/Core/Disassembler.cpp
+++ b/lldb/source/Core/Disassembler.cpp
@@ -1190,7 +1190,7 @@
 }
      
 bool
-PseudoInstruction::DoesBranch () const
+PseudoInstruction::DoesBranch ()
 {
     // This is NOT a valid question for a pseudo instruction.
     return false;