Update constraints to torch 2.4 dynamic_shapes API (#806)

This commit updates to use dynamic_shapes for dynamic dimensions as the
usage of constraints is deprecated in torch 2.4. (The SHARK test checks
out the main branch of this repo and will pass once this is merged)

models/turbine_models/custom_models/resnet_18.py

@@ -56,8 +56,8 @@ class CompiledResnet18Model(CompiledModule):
         params = export_parameters(resnet_model.model)
 
         def main(self, x=AbstractTensor(None, 3, 224, 224, dtype=torch.float32)):
-            const = [x.dynamic_dim(0) < 16]
-            return jittable(resnet_model.forward)(x, constraints=const)
+            dynamic_shapes = {"arg0_1": {0: torch.export.Dim("dim", max=15)}}
+            return jittable(resnet_model.forward)(x, dynamic_shapes=dynamic_shapes)
 
     import_to = "INPUT" if compile_to == "linalg" else "IMPORT"
     inst = CompiledResnet18Model(context=Context(), import_to=import_to)

models/turbine_models/custom_models/stateless_llama.py

@@ -237,8 +237,10 @@ class StateUpdateModule(CompiledModule):
             def run_initialize(
                 self, x=AbstractTensor(BATCH_SIZE, None, dtype=torch.int64)
             ):
-                init_const = [x.dynamic_dim(1) < MAX_STEP_SEQ]
-                token, *state = self.initialize(x, constraints=init_const)
+                dynamic_shapes_init = {
+                    "arg0_1": {1: torch.export.Dim("dim", max=MAX_STEP_SEQ - 1)}
+                }
+                token, *state = self.initialize(x, dynamic_shapes=dynamic_shapes_init)
                 self.global_seq_step = IREE.tensor_dim(
                     state[0], 1
                 )  # ? dimension of arbitrarily 0th kv tensor
@@ -267,16 +269,15 @@ def run_forward(self, x=AbstractTensor(1, 1, dtype=torch.int64)):
                     HIDDEN_DIM,
                     NUM_LAYERS,
                 )
-                forw_const = (
-                    [state_arg[0].dynamic_dim(1) < MAX_STEP_SEQ]
-                    + [
-                        x.dynamic_dim(1) == (state_arg[0].dynamic_dim(1))
-                        for x in state_arg[1:]
-                    ]
-                    + [x.dynamic_dim(1) < MAX_STEP_SEQ for x in state_arg[1:]]
+                state_arg0_dim = torch.export.Dim(
+                    "state_arg0_dim", max=MAX_STEP_SEQ - 1
                 )
+                dynamic_shapes_forw = {"arg0_1": None, "arg1_1": {1: state_arg0_dim}}
+                for state_arg_idx in range(2, len(state_arg) + 1):
+                    current_dim_dict = {f"arg{state_arg_idx}_1": {1: state_arg0_dim}}
+                    dynamic_shapes_forw = {**dynamic_shapes_forw, **current_dim_dict}
                 token, *state_update = self.forward(
-                    x, *state_arg, constraints=forw_const
+                    x, *state_arg, dynamic_shapes=dynamic_shapes_forw
                 )
                 for i in range(NUM_LAYERS):
                     update = IREE.tensor_reshape(
@@ -343,17 +344,19 @@ def run_cached_initialize(
                     HIDDEN_DIM,
                     NUM_LAYERS,
                 )
-                forw_const = (
-                    [x.dynamic_dim(1) < MAX_STEP_SEQ]
-                    + [state_arg[0].dynamic_dim(1) < MAX_STEP_SEQ]
-                    + [
-                        x.dynamic_dim(1) == (state_arg[0].dynamic_dim(1))
-                        for x in state_arg[1:]
-                    ]
-                    + [x.dynamic_dim(1) < MAX_STEP_SEQ for x in state_arg[1:]]
+                state_arg0_dim1 = torch.export.Dim(
+                    "state_arg0_dim1", max=MAX_STEP_SEQ - 1
                 )
+                x_dim = torch.export.Dim("x_dim", max=MAX_STEP_SEQ - 1)
+                dynamic_shapes_forw = {
+                    "arg0_1": {1: x_dim},
+                    "arg1_1": {1: state_arg0_dim1},
+                }
+                for state_arg_idx in range(2, len(state_arg) + 1):
+                    current_dim_dict = {f"arg{state_arg_idx}_1": {1: state_arg0_dim1}}
+                    dynamic_shapes_forw = {**dynamic_shapes_forw, **current_dim_dict}
                 token, *state = self.cached_initialize(
-                    x, *state_arg, constraints=forw_const
+                    x, *state_arg, dynamic_shapes=dynamic_shapes_forw
                 )
                 len_of_new_tokens = IREE.tensor_dim(
                     state[0], 1