ast/test/fixtures/test_grammars/precedence_on_single_child_missing

This language has function calls similar to Ruby's, with no parentheses required, and optional blocks.

There is a shift/reduce conflict here:

foo bar { baz }
       ^

The possible actions are:

1. reduce(expression, 1) - bar is an expression being passed to the foo function.
2. shift - bar is a function being called with the block { baz }

The grammars precedence_on_single_child_negative and precedence_on_single_child_positive show possible resolutions to this conflict.