Numeric literals aren't quite right

Presently this highlights unsized tick notation literals (e.g. 'h18921). These are not actually legal.

Example:
http://alogic-playground.argondesign.com/#N4IghgTg5gziBcIC0B7ABCgrgFzdlADgHRgA2KUAlgMYgA0IlAdgTgGKWkCmc8o+xMhRoIQAMxgBbNFwAeYSQW5pgAHSZo0zTZgAcaMAG51m7Wj1oARsY0Yc5/TBsm0ANxSUAJmklhmACgBKFRdNGDQAXgM0AGorWLQAcgALADYbTU0xLiZqLgy0AF91QpBCwqA=