TableGen: Remove assert that pattern results match input number

[arsenm]

Summary

AMDGPU has some atomic instructions that do not return the previous
result, and can only be selected if there are no uses. The source
pattern will only match if the use is empty, so it should be safe to
discard the result.

[arsenm]

ping

[arsenm]

ping

[hfinkel]

LGTM

[arsenm]

9f9f42dbc5f54bbee6785a62acc8cd7e5ed12ea5

utils/TableGen/DAGISelMatcherGen.cpp

if (!Pattern.getDstRegs().empty()) {
     }
 
     for (Record *Reg : Pattern.getDstRegs()) {
       if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue;
       ++NumSrcResults;
     }
   }
 
-  assert(Ops.size() >= NumSrcResults && "Didn't provide enough results");
   SmallVector<unsigned, 8> Results(Ops);
 
   // Apply result permutation.
   for (unsigned ResNo = 0; ResNo < Pattern.getDstPattern()->getNumResults();
        ++ResNo) {
     Results[ResNo] = Ops[Pattern.getDstPattern()->getResultIndex(ResNo)];
   }