[FRONTEND] Complete rewrite of the runtime (#644)

This PR completely rewrites the runtime of Triton to be more lean and
clearly separate the compilation step from the just-in-time caching logic.
This should substantially reduce launch overhead.

python/test/unit/operators/test_matmul.py

@@ -78,10 +78,9 @@ def test_op(BLOCK_M, BLOCK_N, BLOCK_K, SPLIT_K, NWARP, NSTAGE, M, N, K, AT, BT,
     pre_hook = None if SPLIT_K == 1 else lambda nargs: nargs['C'].zero_()
     configs = [triton.Config(kwargs=kwargs, num_warps=NWARP, num_stages=NSTAGE, pre_hook=pre_hook)]
     kernel = triton.ops._matmul.kernel
-    decorators = kernel.kernel_decorators
-    kernel.kernel_decorators = []
-    triton.autotune(configs, [])(kernel)
-    kernel.kernel_decorators += decorators[1:]
+    kernel.configs = configs
+    # kernel.run = kernel.run.run.run
+
     # get matrix shape
     M = BLOCK_M if M is None else M
     N = BLOCK_N if N is None else N