[llvm] [ADT] Make use of subsetOf and anyCommon methods of BitVector (NFC) (PR #170876)

[Jakub Kuderski via llvm-commits]

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@@ -274,9 +274,11 @@ static Error randomizeMCOperand(const LLVMState &State,
     break;
   case MCOI::OperandType::OPERAND_REGISTER: {
     assert(Op.isReg());
-    const BitVector &AllowedRegs = Op.getRegisterAliasing().sourceBits();
+    auto AllowedRegs = Op.getRegisterAliasing().sourceBits();
     assert(AllowedRegs.size() == ForbiddenRegs.size());
-    if (AllowedRegs.subsetOf(ForbiddenRegs))
+    for (auto I : ForbiddenRegs.set_bits())
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kuhar wrote:

nit: these types should be spelled out since they are not obvious based on the immediate context per https://llvm.org/docs/CodingStandards.html#use-auto-type-deduction-to-make-code-more-readable

https://github.com/llvm/llvm-project/pull/170876