Fix a crash when formatting some dicts with parenthesis-wrapped long
string keys. When LL[0] is an atom string, we need to check the atom
node's siblings instead of LL[0] itself, e.g.:
dictsetmaker
atom
STRING '"This is a really long string that can\'t be expected to fit in one line and is used as a nested dict\'s key"'
/atom
COLON ':'
atom
LSQB ' ' '['
listmaker
STRING '"value"'
COMMA ','
STRING ' ' '"value"'
/listmaker
RSQB ']'
/atom
COMMA ','
/dictsetmaker
e2adcd7de1