Both C and C++ have "bool", "true" and "false" in lower case; C
requires <stdbool.h> for this, in C++ it is an inherent type built
into the compiler. Use those instead of the old macros; emulate with
a simple typedef enum if unavailable.
Change cloc_t to struct location, and reorder the members so that it
should fit in 16 bytes instead of needing 8 bytes of extra padding on
64-bit machines.
Change loc_t to cloc_t to avoid AIX conflict.
We really shouldn't use _t names at all; they are usually considered
platform types, but worry about that later.
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.)
Add special operators to allow the use of floating-point constants in
contexts other than DW/DD/DQ/DT/DO.
As part of this checkin, make MAX_KEYWORD generated by tokhash.pl,
since it knows what all the keywords are so it can tell which one is
the longest.
