[PowerPC] Add branch flag on asm parser-only branch instructions

This flag was missing but it wasn't an issue as nothing depended on it
for these asm parser-only instructions. Now that LLDB support is slowly
landing, it is important to get this right.
Committing on behalf of Leonardo Bianconi.

Differential revision: https://reviews.llvm.org/D40846


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320475 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/PPCInstrInfo.td

@@ -4336,7 +4336,7 @@ def RLWNMobm : PPCAsmPseudo<"rlwnm. $rA, $rS, $n, $b",
 
 // These generic branch instruction forms are used for the assembler parser only.
 // Defs and Uses are conservative, since we don't know the BO value.
-let PPC970_Unit = 7 in {
+let PPC970_Unit = 7, isBranch = 1 in {
   let Defs = [CTR], Uses = [CTR, RM] in {
     def gBC : BForm_3<16, 0, 0, (outs),
                       (ins u5imm:$bo, crbitrc:$bi, condbrtarget:$dst),