Allow Cython keywords to be used as names.

Only cdef, cpdef, and ctypedef are dissallowed.

Cython/Parser/Grammar

@@ -22,10 +22,10 @@ eval_input: testlist NEWLINE* ENDMARKER
 decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
 decorators: decorator+
 decorated: decorators (classdef | funcdef)
-funcdef: 'def' NAME parameters ':' suite
+funcdef: 'def' PY_NAME parameters ':' suite
 parameters: '(' [varargslist] ')'
 varargslist: ((fpdef ['=' test] ',')*
-              ('*' NAME [',' '**' NAME] | '**' NAME) |
+              ('*' PY_NAME [',' '**' PY_NAME] | '**' PY_NAME) |
               fpdef ['=' (test | '*')] (',' fpdef ['=' (test | '*')])* [',']
               ['.' '.' '.'])
 fpdef: maybe_typed_name | '(' fplist ')'
@@ -54,19 +54,19 @@ import_stmt: import_name | import_from
 import_name: ('import' | 'cimport') dotted_as_names
 import_from: ('from' ('.'* dotted_name | '.'+)
               ('import' | 'cimport') ('*' | '(' import_as_names ')' | import_as_names))
-import_as_name: NAME ['as' NAME]
-dotted_as_name: dotted_name ['as' NAME]
+import_as_name: PY_NAME ['as' PY_NAME]
+dotted_as_name: dotted_name ['as' PY_NAME]
 import_as_names: import_as_name (',' import_as_name)* [',']
 dotted_as_names: dotted_as_name (',' dotted_as_name)*
-dotted_name: NAME ('.' NAME)*
-global_stmt: 'global' NAME (',' NAME)*
+dotted_name: PY_NAME ('.' PY_NAME)*
+global_stmt: 'global' PY_NAME (',' PY_NAME)*
 exec_stmt: 'exec' expr ['in' test [',' test]]
 assert_stmt: 'assert' test [',' test]
 
 compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
 if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
 while_stmt: 'while' test ':' suite ['else' ':' suite]
-for_stmt: 'for' exprlist ('in' testlist | 'from' expr comp_op NAME comp_op expr ['by' expr])':' suite ['else' ':' suite]
+for_stmt: 'for' exprlist ('in' testlist | 'from' expr comp_op PY_NAME comp_op expr ['by' expr])':' suite ['else' ':' suite]
 try_stmt: ('try' ':' suite
            ((except_clause ':' suite)+
             ['else' ':' suite]
@@ -106,11 +106,11 @@ atom: ('(' [yield_expr|testlist_comp] ')' |
        '{' [dictorsetmaker] '}' |
        '`' testlist1 '`' |
        new_expr |
-       NAME | NUMBER | STRING+)
+       PY_NAME | NUMBER | STRING+)
 listmaker: test ( list_for | (',' test)* [','] )
 testlist_comp: test ( comp_for | (',' test)* [','] )
 lambdef: 'lambda' [varargslist] ':' test
-trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
+trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' PY_NAME
 subscriptlist: subscript (',' subscript)* [',']
 subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
@@ -119,7 +119,7 @@ testlist: test (',' test)* [',']
 dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
                   (test (comp_for | (',' test)* [','])) )
 
-classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
+classdef: 'class' PY_NAME ['(' [testlist] ')'] ':' suite
 
 arglist: (argument ',')* (argument [',']
                          |'*' test (',' argument)* [',' '**' test]
@@ -150,8 +150,8 @@ signedness: 'unsigned' | 'signed'
 longness: 'char' | 'short' | 'long' | 'long' 'long'
 int_type: signedness [longness] | longness | [signedness] [longness] ('int' | 'double')  | 'complex' # TODO: [unsigned] double doesn't make sens, but we need long double
 
-type: ['const'] (NAME ('.' NAME)* | int_type) ['complex'] [type_qualifiers]
-maybe_typed_name: ['const'] (NAME [('.' NAME)* ['complex'] [type_qualifiers] NAME] | int_type ['complex'] [type_qualifiers] NAME)
+type: ['const'] (NAME ('.' PY_NAME)* | int_type) ['complex'] [type_qualifiers]
+maybe_typed_name: ['const'] (NAME [('.' PY_NAME)* ['complex'] [type_qualifiers] NAME] | int_type ['complex'] [type_qualifiers] NAME)
 teplate_params: '[' NAME (',' NAME)* ']'
 type_qualifiers: type_qualifier+
 type_qualifier: '*' | '**' | '&' | type_index
@@ -174,15 +174,16 @@ ctypedef_stmt: 'ctypedef' (cvar_decl | struct | enum)
 # Requires a type
 cvar_decl: [visibility] type cname (NEWLINE | cfunc)
 # Allows an assignment
-cvar_def: maybe_typed_name (['=' test] (',' NAME ['=' test])* NEWLINE | cfunc)
+cvar_def: maybe_typed_name (['=' test] (',' PY_NAME ['=' test])* NEWLINE | cfunc)
 
 visibility: 'public' | 'api' | 'readonly' | 'extern'
 cfunc: [teplate_params] parameters [gil_spec] [exception_value] (':' suite | NEWLINE)
-exception_value: 'except' (['?'] expr | '*' | '+' [NAME])
+exception_value: 'except' (['?'] expr | '*' | '+' [PY_NAME])
 gil_spec: 'with' ('gil' | 'nogil') | 'nogil'
 
+cname: NAME [STRING]
 cclass: classdef
-fused: 'fused' NAME ':' NEWLINE INDENT ( type NEWLINE)+ DEDENT
+fused: 'fused' PY_NAME ':' NEWLINE INDENT ( type NEWLINE)+ DEDENT
 enum: 'enum' [cname] (NEWLINE | ':' enum_suite)
 enum_suite: NEWLINE INDENT (cname ['=' NUMBER] NEWLINE | pass_stmt NEWLINE)+ DEDENT
 struct: ('struct' | 'union') cname (NEWLINE | (':' struct_suite))
@@ -194,4 +195,7 @@ cppclass_suite: NEWLINE INDENT (cvar_decl | ctype_decl | pass_stmt NEWLINE)+ DED
 extern_block: 'extern' 'from' ('*' | STRING) ['namespace' STRING] [gil_spec] ':' (pass_stmt | extern_suite)
 extern_suite: NEWLINE INDENT (['cdef' | 'cpdef'] (cvar_decl | cdef_type_decl) | ctypedef_stmt)+ DEDENT
 
-cname: NAME [STRING]
+cy_type_kwd: 'struct' | 'union' | 'fused' | 'cppclass' | 'int' | 'double' | 'complex'
+cy_kwd: cy_type_kwd | signedness | longness | visibility | 'gil' | 'nogil' | 'namespace' | 'const' | 'by'
+PY_NAME: NAME | cy_kwd
+