fix[lang]: add raw_log() constancy check (#4201)

disallow `raw_log()` from being called within staticcall context.

tests/functional/syntax/exceptions/test_constancy_exception.py

@@ -130,6 +130,18 @@ def bar()->DynArray[uint16,3]:
 @view
 def topup(amount: uint256):
     assert extcall self.token.transferFrom(msg.sender, self, amount)
+    """,
+        """
+@external
+@view
+def foo(_topic: bytes32):
+    raw_log([_topic], b"")
+    """,
+        """
+@external
+@pure
+def foo(_topic: bytes32):
+    raw_log([_topic], b"")
     """,
     ],
 )

vyper/builtins/functions.py

@@ -1267,6 +1267,8 @@ def infer_arg_types(self, node, expected_return_typ=None):
 
     @process_inputs
     def build_IR(self, expr, args, kwargs, context):
+        context.check_is_not_constant(f"use {self._id}", expr)
+
         topics_length = len(expr.args[0].elements)
         topics = args[0].args
         topics = [unwrap_location(topic) for topic in topics]