bug#36432: 26.2; SMIE does not request forward tokens when point is at point-max

[Sam Halliday]

SMIE (via a `indent-for-tab-command') does not request forward tokens
from the lexer when point is at `point-max'.

This might sound like a strange bug report: why should smie expect
there to be any tokens when it is already at point-max? The answer is:
virtual tokens. For example, Haskell may have many closing curly
brackets that live at the end of the buffer.

A workaround is to add a few stray newlines to the end of any buffer
that uses SMIE for indentation. Then SMIE will request the next tokens
(even thought there is only whitespace left until the end of the
buffer) and will receive at least one of those virtuals.