opting for skipping PEP492 backwards compatibility magic, instead directly making await and async keywords

See discussion at
https://github.com/davidhalter/jedi/pull/691#issuecomment-182815864

jedi/api/keywords.py

@@ -1,7 +1,7 @@
 import pydoc
 import keyword
 
-from jedi._compatibility import is_py3
+from jedi._compatibility import is_py3, is_py35
 from jedi import common
 from jedi.evaluate.helpers import FakeName
 from jedi.parser.tree import Leaf
@@ -12,7 +12,12 @@ except ImportError:
     import pydoc_topics
 
 if is_py3:
-    keys = keyword.kwlist
+    if is_py35:
+        # in python 3.5 async and await are not proper keywords, but for
+        # completion pursposes should as as though they are
+        keys = keyword.kwlist + ["async", "await"]
+    else:
+        keys = keyword.kwlist
 else:
     keys = keyword.kwlist + ['None', 'False', 'True']
 

jedi/parser/grammar3.5.txt

@@ -23,7 +23,9 @@ decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
 decorators: decorator+
 decorated: decorators (classdef | funcdef | async_funcdef)
 
-async_funcdef: ASYNC funcdef
+# NOTE: Reinoud Elhorst, using ASYNC/AWAIT keywords instead of tokens
+# skipping python3.5 compatibility, in favour of 3.7 solution
+async_funcdef: 'async' funcdef
 funcdef: 'def' NAME parameters ['->' test] ':' suite
 
 parameters: '(' [typedargslist] ')'
@@ -69,7 +71,7 @@ nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
 assert_stmt: 'assert' test [',' test]
 
 compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
-async_stmt: ASYNC (funcdef | with_stmt | for_stmt)
+async_stmt: 'async' (funcdef | with_stmt | for_stmt)
 if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
 while_stmt: 'while' test ':' suite ['else' ':' suite]
 for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
@@ -106,7 +108,7 @@ arith_expr: term (('+'|'-') term)*
 term: factor (('*'|'@'|'/'|'%'|'//') factor)*
 factor: ('+'|'-'|'~') factor | power
 power: atom_expr ['**' factor]
-atom_expr: [AWAIT] atom trailer*
+atom_expr: ['await'] atom trailer*
 atom: ('(' [yield_expr|testlist_comp] ')' |
        '[' [testlist_comp] ']' |
        '{' [dictorsetmaker] '}' |