NanoBlaze: the expandable processor

The perl script assembler fails to distinguish between labels that differ only in that one has a single digit appended. For example, these two labels are OK: "test_val1" and "test_val2" but these two do not work: "test_val" and "test_val1"

It appears to be OK if the additional character is a non-digit character. For example, these are OK: "test_val" and "test_vala"

Bug found. If two labels are such that one is a substring of the other, then the substitute operation for labels (line 260) may fail if the hash table is such that the shorter label (the substring) appears first. The simple solution is to never allow labels which are substrings of other labels. The same would appear to apply to constants, since a similar substitute operation occurs on line 256.