The files ltest.out and ltest.err were the result of running the sample
input through the lexer tester as follows:
	gcc -E ltests/*.c | ./lextest >ltest.out 2>ltest.err

tokens-manual.h contains an enum definition for the token codes used in
the above sample lexer program.  If you want your output to be diff-able
against the reference test output, make sure to use the same textual
representation (names) for the tokens and to adhere to the format defined
in the assignment worksheet.  Otherwise you'll have to compare by hand.