This patch simply restores the deleted files unchanged, except for the
following:
o Makefile.ref now generates the js-config.h header file, based on the
values of JS_THREADSAFE and JS_GC_ZEAL it is invoked with.
o The subdirectory containing platform-specific files for Makefile.ref
has been renamed from 'config' to 'ref-config'; the former name
conflicts with the new unified build system. config.mk has been
updated accordingly.
SpiderMonkey has, at present, two separate build systems: one used for
in-tree builds, and one used for SpiderMonkey-only builds.
The former is constituted entirely by js/src/Makefile.in. This is a
typical Mozilla makefile, leaning on the top-level config/*.mk files
for most of the details.
The latter is comprised by a shadow build system, all in js/src:
Makefile.ref, config.mk, rules.mk, jsconfig.mk, and config/*.mk.
These are superseded by the separate build system implemented in a
later patch; we delete them all here.
This patch consists entirely of deletions; there are no textual changes.