[rewriter] Remove generic pattern matcher (#2567)

It is obsolete and the capability is covered by the simple pattern
matcher.

---------

Signed-off-by: Justin Chu <justinchuby@users.noreply.github.com>

Author: justinchuby

.lintrunner.toml

@@ -57,7 +57,6 @@ exclude_patterns = [
     'onnxscript/rewriter/onnxruntime/transformers/multihead_attention.py',  # FIXME
     'onnxscript/tools/function_unittest_producer.py',  # FIXME
     'onnxscript/rewriter/onnxruntime/transformers/layernorm.py',  # FIXME
-    'onnxscript/rewriter/generic_pattern.py',  # FIXME
 ]
 command = [
     'python',

examples/pattern_rewriting.py

@@ -141,28 +141,3 @@ def rotary_apply_pattern(op, x, pos_ids, axis):
 rule = pattern.RewriteRule(rotary_match_pattern, rotary_apply_pattern, verbose=10)
 
 rule.apply_to_model(ir_model)
-
-# TODO(rama): Update the following, the trace-printed looks different now.
-
-######################################
-# The logs shows every time the algorithm rejected a pattern.
-# We can see the following:
-#
-# ::
-#
-#     [OnnxGenericPattern.match] NONE - line: 673:onnxscript.rewriter.generic_pattern, op_type=Cast
-#         --hint--: BACKWARD: different node types
-#           --pattern
-#           ConcatTraining(transpose, transpose) -> (output, length)
-#           -- model
-#           ConcatTrainingBad(_onx_transpose0, _onx_transpose0) -> (_onx_concattraining0, _onx_concattraining1)
-#         iteration=1
-#         --marked-- #2
-#           Cast(_onx_cos0) ~ Cast(cos) [140186194226496-140186194222320]
-#           Cos(_onx_concattraining0) ~ Cos(output) [140186194230816-140186194223472]
-#         len(stacked)=0:[]
-#
-# Line 673 in file `generic_pattern.py`, the match was rejected.
-# It says while comparing two nodes in the backward direction,
-# node types do not match.
-# It also says that two nodes were actually matched.

onnxscript/rewriter/_rewrite_rule.py

@@ -82,12 +82,7 @@ def __init__(
         if isinstance(matcher, _matcher.PatternMatcher):
             self._matcher = matcher
         elif matcher is None:
-            if target_pattern.has_single_output_node:
-                self._matcher = _matcher.SimplePatternMatcher(self._target_pattern)
-            else:
-                import onnxscript.rewriter.generic_pattern as generic_pattern
-
-                self._matcher = generic_pattern.GenericPatternMatcher(self._target_pattern)
+            self._matcher = _matcher.SimplePatternMatcher(self._target_pattern)
         else:
             self._matcher = matcher(self._target_pattern)
         self._verbose = verbose