SIL: Remove workaround for rdar://problem/36799163

Author: slavapestov

lib/SIL/SILVerifier.cpp

@@ -2342,14 +2342,6 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
         case SILInstructionKind::ApplyInst:
         case SILInstructionKind::TryApplyInst:
         case SILInstructionKind::PartialApplyInst:
-          // Non-Mutating set pattern that allows a inout (that can't really
-          // write back. Only SILGen generates PointerToThinkFunction
-          // instructions in the writeback code.
-          if (auto *AI = dyn_cast<ApplyInst>(inst)) {
-            if (isa<PointerToThinFunctionInst>(AI->getCallee())) {
-              break;
-            }
-          }
           if (isConsumingOrMutatingApplyUse(use))
             return true;
           else