gh-133412: amend docs for the `inst` definition (#133708)

The `stack_effect` is incorrectly documented as being allowed to be optional.

diff --git a/Tools/cases_generator/interpreter_definition.md b/Tools/cases_generator/interpreter_definition.md
index 1ee4306f3eac1d9a4e8af5d25eca4a621b12ec3f..72020133738fa515d3b72c5132374fb31e7e1525 100644 (file)
--- a/Tools/cases_generator/interpreter_definition.md
+++ b/Tools/cases_generator/interpreter_definition.md
@@ -81,7 +81,7 @@ and a piece of C code describing its semantics:
     (definition | family | pseudo)+
 
   definition:
-    "inst" "(" NAME ["," stack_effect] ")" "{" C-code "}"
+    "inst" "(" NAME "," stack_effect ")" "{" C-code "}"
     |
     "op" "(" NAME "," stack_effect ")" "{" C-code "}"
     |