cchecklink: added option "-files-from" to read .sdump file names
from a file or from standard input.
build_from_parsed: simplified code + correctness proof.
Revised parsing of command-line arguments (in preparation for adding more).
Honor "ccomp -E foo.h" for GCC compatibility.
Accept .o.ext files as object files for GCC compatibility.
Fixed and improved handling of Cminor source files.
Add flags to control individual optimization passes + flag -O0 for turning them off.
Analysis of jump tables was using the wrong size.
Use gettimeofday() instead of obsolete ftime().
(Patch by Daniel Dickman.)
Record public global definitions via field "prog_public" in AST.program.
For the moment, this field is ignored.
Add Genv.public_symbol operation.
Restrict pointer event values to public global names.
Update proofs accordingly.  PowerPC and ARM need updating.
Verification of the Unusedglob pass (removal of unreferenced static global definitions).  Assorted changes to ia32/Op.v.  PowerPC and ARM need updating.
Update PowerPC port.
Update the ARM port.