[CIR][CIRGen][Builtin] Support __builtin_elementwise_abs with vector of floating type (llvm#1174)

[PR1132](llvm/clangir#1132) implements missing
feature `fpUnaryOPsSupportVectorType`, so revisit this code.

One another thing changed is that I stopped using
`cir::isAnyFloatingPointType` as it contains types like long double and
FP80 which are not supported by the [builtin's
signature](https://clang.llvm.org/docs/LanguageExtensions.html#vector-builtins)

Author: ghehg

clang/include/clang/CIR/MissingFeatures.h

@@ -410,9 +410,6 @@ struct MissingFeatures {
 
   //-- Other missing features
 
-  // We need to extend fpUnaryOPs to support vector types.
-  static bool fpUnaryOPsSupportVectorType() { return false; }
-
   // We need to track the parent record types that represent a field
   // declaration. This is necessary to determine the layout of a class.
   static bool fieldDeclAbstraction() { return false; }

clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp

@@ -3124,10 +3124,12 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
     mlir::Type cirTy = ConvertType(E->getArg(0)->getType());
     bool isIntTy = cir::isIntOrIntVectorTy(cirTy);
     if (!isIntTy) {
-      if (cir::isAnyFloatingPointType(cirTy)) {
+      mlir::Type eltTy = cirTy;
+      if (mlir::isa<cir::VectorType>(cirTy))
+        eltTy = mlir::cast<cir::VectorType>(cirTy).getEltType();
+      if (mlir::isa<cir::SingleType, cir::DoubleType>(eltTy)) {
         return emitUnaryFPBuiltin<cir::FAbsOp>(*this, *E);
       }
-      assert(!MissingFeatures::fpUnaryOPsSupportVectorType());
       llvm_unreachable("unsupported type for BI__builtin_elementwise_abs");
     }
     mlir::Value arg = emitScalarExpr(E->getArg(0));