Fix a tblgen bug.

Fix a tblgen bug.

Given the pattern below as an example:
list<dag> Pattern = [(set RC:$dst, (v4f32 (shufp:src3 RC:$src1,
                            (mem_frag addr:$src2))))];

The right reference resolving should lead to:
list<dag> Pattern = [(set VR128:$dst, (v4f32 (shufp:src3 VR128:$src1,
                            (mem_frag addr:$src2))))];
But was yielding:
list<dag> Pattern = [(set VR128:$dst, (v4f32 (shufp VR128:$src1,
                            (mem_frag addr:$src2))))];

Fix this by passing the right name when creating a new DagInit node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106670 91177308-0d34-0410-b5e6-96231b3b80d8