port hardtanh and add hardtanh test

Summary: titled

Differential Revision: D72405686

Author: zonglinpeng

backends/cadence/fusion_g3/operators/targets.bzl

@@ -40,6 +40,7 @@ OPERATORS = [
     "rsqrt",
     "sigmoid",
     "sqrt",
+    "hardtanh",
     "tanh",
     "transpose_copy",
     "where",

backends/cadence/utils/facto_util.py

@@ -99,6 +99,7 @@ def apply_scalar_contraints(op_name: str) -> list[ScalarDtype]:
     match op_name:
         case "add.Scalar" | "sub.Scalar" | "mul.Scalar" | "div.Scalar":
             return [ScalarDtype.int]
+        
         case _:
             return [ScalarDtype.float, ScalarDtype.int]
 
@@ -122,6 +123,11 @@ def facto_testcase_gen(op_name: str) -> List[Tuple[List[str], OrderedDict[str, s
                         cp.Size.Le(lambda deps, r, d: 2**2),
                     ]
                 )
+            if in_spec.name == "max_val": # hardtanh
+                spec.inspec[index].deps = [0, 1]
+                spec.inspec[index].constraints.extend(
+                    [cp.Value.Ge(lambda deps, _: deps[1])]
+                )
             else:
                 spec.inspec[index].constraints.extend(
                     [