Add explicit lint-comment-style fallthrough annotations. GCC now assumes that if you don't have these you're making a mistake, which is annoying. XXX: This changeset updates the AG output files only (by hand) and is XXX: abusive - rebuilding them will erase the change. However, I need XXX: to get things to build before I can try to get AG to issue the XXX: annotations itself, so this seems like a reasonable expedient.

  /* test.ffc  - test file for ffcalc.syn grammar */

  (156.7-8.2+1.5)/3 - 7*7     /*  1  */

F=32
C = (5/9)*(F-32)         /* Fahrenheit to Centigrade */

a=3
a= 10*(10*(10*(a+7)))        /*  nested parentheses  */

m=3
b=9
x=7
 y = m*x + b                /*  2-D line  */