move coverage plugin to separate package and add function to

check if an instruction has previously been covered

mythril/laser/ethereum/plugins/implementations/coverage/__init__.py

@@ -0,0 +1 @@
+from mythril.laser.ethereum.plugins.implementations.coverage.coverage_plugin import InstructionCoveragePlugin

mythril/laser/ethereum/plugins/implementations/coverage/coverage_plugin.py

@@ -87,3 +87,12 @@ class InstructionCoveragePlugin(LaserPlugin):
         for _, cv in self.coverage.items():
             total_covered_instructions += sum(cv[1])
         return total_covered_instructions
+
+    def is_instruction_covered(self, bytecode, index):
+        if bytecode not in self.coverage.keys():
+            return False
+
+        try:
+            return self.coverage[bytecode][index]
+        except IndexError:
+            return False