Concentrate compiler dependencies to compiler.h; make sure compiler.h
is included first in every .c file (since some prototypes may depend
on the presence of feature request macros.)
Actually use the conditional inclusion of various functions (totally
broken in previous releases.)
Switch the preprocessor over to using the hash table library. On my
system, this improves the runtime of the output of test/pref/macro.pl
from over 600 seconds to 7 seconds.
Macros have an odd mix of case-sensitive and case-insensitive
behaviour, plus there are matching parameters for arguments, etc. As
a result, we use case-insensitive hash tables and use a linked list to
store all the possible isomorphs.
Use the new hash table function library to store labels. When
compiling on my 64-bit system, it reduces the assembly time for the
output of test/perf/label.pl from 73 to 7 seconds.
