This separates the 32-bit sysv/linux/bsd code from the 64-bit linux

code, and makes it possible to link code compiled with different
options to those used to compile libffi.  For example, a
-mlong-double-128 libffi can be used with -mlong-double-64 code.

Using the return value area as a place to pass parameters wasn't such
a good idea, causing a failure of cls_ulonglong.c.  I didn't see this
when running the mainline gcc libffi testsuite because that version of
the test is inferior to the upstreamm libffi test.

Using NUM_FPR_ARG_REGISTERS rather than NUM_FPR_ARG_REGISTERS64 meant
that a parameter save area could be allocated before it was strictly
necessary.  Wrong but harmless.  Found when splitting apart ffi.c
into 32-bit and 64-bit support.

include/ffi.h.in

@@ -221,6 +221,11 @@ typedef struct {
 #endif
 } ffi_cif;
 
+#if HAVE_LONG_DOUBLE_VARIANT
+/* Used to adjust size/alignment of ffi types.  */
+void ffi_prep_types (ffi_abi abi);
+# endif
+
 /* Used internally, but overridden by some architectures */
 ffi_status ffi_prep_cif_core(ffi_cif *cif,
 			     ffi_abi abi,