[clang] [llvm] [clang] Reland Add tanf16 builtin and support for tan constrained intrinsic (PR #94559)

[Farzon Lotfi via cfe-commits]

================
@@ -2923,6 +2923,18 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
       SetSqrtFPAccuracy(Call);
       return RValue::get(Call);
     }
+
+    case Builtin::BItan:
----------------
farzonl wrote:

def TanF16F128 : Builtin, F16F128MathTemplate = BI_builtin_tanf
vs 
def Tan : FPMathTemplate, LibBuiltin<"math.h">  = BItanf

https://github.com/llvm/llvm-project/pull/94559