bpo-23896: Add a grammar where exec isn't a stmt (#13272)

https://bugs.python.org/issue23896

Lib/lib2to3/pygram.py

@@ -36,5 +36,8 @@ python_symbols = Symbols(python_grammar)
 python_grammar_no_print_statement = python_grammar.copy()
 del python_grammar_no_print_statement.keywords["print"]
 
+python_grammar_no_print_and_exec_statement = python_grammar_no_print_statement.copy()
+del python_grammar_no_print_and_exec_statement.keywords["exec"]
+
 pattern_grammar = driver.load_packaged_grammar("lib2to3", _PATTERN_GRAMMAR_FILE)
 pattern_symbols = Symbols(pattern_grammar)

Misc/ACKS

@@ -1860,3 +1860,4 @@ Carsten Klein
 Diego Rojas
 Edison Abahurire
 Geoff Shannon
+Batuhan Taskaya

Misc/NEWS.d/next/Library/2019-05-13-05-49-15.bpo-23896.8TtUKo.rst

@@ -0,0 +1,2 @@
+Adds a grammar to lib2to3.pygram that contains exec as a function not as
+statement.