Accept decay rate parameter in MockCompilationRunner

The mock used in generate_default_trace_test needs to accept
moving_average_decay_rate as it is automatically passed in by the
instantiation setup in generate_trace in generate_default_trace.py. The
test still passes if it isn't this way, but doesn't actually "compile" any
modules due to the errors, which sort of defeats the point.

Author: boomanaiden154

compiler_opt/tools/generate_default_trace_test.py

@@ -38,7 +38,8 @@
 class MockCompilationRunner(compilation_runner.CompilationRunner):
   """A compilation runner just for test."""
 
-  def __init__(self, sentinel=None):
+  def __init__(self, moving_average_decay_rate: float, sentinel=None):
+    del moving_average_decay_rate  # Unused.
     assert sentinel == 42
     super().__init__()