Reorganize how tb infrstructure selects toolchains

tests/lib/simulators/base.py

@@ -0,0 +1,31 @@
+from typing import TYPE_CHECKING, List
+
+if TYPE_CHECKING:
+    from ..sim_testcase import SimTestCase
+
+class Simulator:
+    name = ""
+
+    @classmethod
+    def is_installed(cls) -> bool:
+        raise NotImplementedError
+
+    def __init__(self, testcase: 'SimTestCase' = None) -> None:
+        self.testcase = testcase
+
+    @property
+    def tb_files(self) -> List[str]:
+        files = []
+        files.extend(self.testcase.cpuif.get_sim_files())
+        files.extend(self.testcase.get_extra_tb_files())
+        files.append("regblock_pkg.sv")
+        files.append("regblock.sv")
+        files.append("tb.sv")
+
+        return files
+
+    def compile(self) -> None:
+        raise NotImplementedError
+
+    def run(self, plusargs:List[str] = None) -> None:
+        raise NotImplementedError