Revert "[WebAssembly] Constant fold wasm.dot" (#152382)

Reverts #149619

It breaks ubsan bot:
https://lab.llvm.org/buildbot/#/builders/25/builds/10523

Earlier today the failure was hidden by another breakage that is fixed
now.

Author: alazarev

llvm/lib/Analysis/ConstantFolding.cpp

@@ -1659,7 +1659,6 @@ bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
   case Intrinsic::aarch64_sve_convert_from_svbool:
   case Intrinsic::wasm_alltrue:
   case Intrinsic::wasm_anytrue:
-  case Intrinsic::wasm_dot:
   // WebAssembly float semantics are always known
   case Intrinsic::wasm_trunc_signed:
   case Intrinsic::wasm_trunc_unsigned:
@@ -3990,30 +3989,6 @@ static Constant *ConstantFoldFixedVectorCall(
     }
     return ConstantVector::get(Result);
   }
-  case Intrinsic::wasm_dot: {
-    unsigned NumElements =
-        cast<FixedVectorType>(Operands[0]->getType())->getNumElements();
-
-    assert(NumElements == 8 && Result.size() == 4 &&
-           "wasm dot takes i16x8 and produces i32x4");
-    assert(Ty->isIntegerTy());
-    int32_t MulVector[8];
-
-    for (unsigned I = 0; I < NumElements; ++I) {
-      ConstantInt *Elt0 =
-          cast<ConstantInt>(Operands[0]->getAggregateElement(I));
-      ConstantInt *Elt1 =
-          cast<ConstantInt>(Operands[1]->getAggregateElement(I));
-
-      MulVector[I] = Elt0->getSExtValue() * Elt1->getSExtValue();
-    }
-    for (unsigned I = 0; I < Result.size(); I++) {
-      int32_t IAdd = MulVector[I * 2] + MulVector[I * 2 + 1];
-      Result[I] = ConstantInt::get(Ty, IAdd);
-    }
-
-    return ConstantVector::get(Result);
-  }
   default:
     break;
   }