revert <> error message, update tests

Author: Aniketsy

Lib/test/test_syntax.py

@@ -3533,27 +3533,27 @@ def test_double_ampersand(self):
     def test_diamond_operator(self):
         self._check_error(
             "1<>2",
-            r'Are you trying to overthrow the SC\?  Use operator "!="!',
+            "invalid syntax",
             lineno=1,
             end_lineno=1,
             offset=2,
             end_offset=4,
         )
-        self._check_error(
-            "1 < > 2",
-            "invalid syntax",
-            lineno=1,
-            end_lineno=1,
-            offset=5,
-            end_offset=6,
-        )
 
     def test_diamond_operator_barry_as_flufl(self):
         # Under barry_as_FLUFL, '<>' is the valid "not equal" operator
         compile(
             "from __future__ import barry_as_FLUFL\n1<>2",
             "<test>", "exec",
         )
+        self._check_error(
+            "from __future__ import barry_as_FLUFL\na < > b",
+            "invalid syntax",
+            lineno=2,
+            end_lineno=2,
+            offset=5,
+            end_offset=6,
+        )
 
     def test_triple_equal(self):
         self._check_error(

Parser/action_helpers.c

@@ -931,10 +931,6 @@ _PyPegen_check_barry_as_flufl(Parser *p, Token* t) {
         return -1;
     }
     if (!(p->flags & PyPARSE_BARRY_AS_BDFL)) {
-        if (strcmp(tok_str, "<>") == 0) {
-            RAISE_SYNTAX_ERROR("invalid syntax.  Are you trying to overthrow the SC?  Use operator \"!=\"!");
-            return -1;
-        }
         return strcmp(tok_str, "!=");
     }
     return 0;