chd: make LZMA and inline helpers portable

chd: make LZMA and inline helpers portable

Use the public LZMA property writer to build decoder properties
instead of the MAME-only allocator helper. This keeps the CHD LZMA
path compatible with the stock SDK interface.

Make ATTR_FORCE_INLINE produce inline definitions on GCC and Clang so
header-defined helpers can be included safely by multiple translation
units. Define PTR64 from CPU_64_BIT when the build has not already
provided it.