As per discussion with Ulrich Weigand, document the restrictions
on the code within ffi_call_int as we simultaneously prepare
stack frames for ffi_call_SYSV and the target function.

It's silly to stick to esa/390 features when the compiler won't.
Detect when brasl and larl are used by the compiler and then use
them in the assembly.

Avoid using ffi_prep_args as a callback; do all the work setting
up the frame within ffi_call_int directly.  Save fewer registers
in ffi_closure_SYSV.

	* src/types.c (FFI_TYPEDEF, FFI_NONCONST_TYPEDEF): Merge the macros by
	adding another argument that controls whether the result is const or not
	(FFI_LDBL_CONST): Temporary macro to reduce ifdef confusion
	* src/prep_cif.c (ffi_prep_cif_core): Replace list of systems with new
	macro FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
	* src/pa/ffitarget.h (FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION):
	Define.
	* src/s390/ffitarget.h (FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION):
	Define.
	* src/x86/ffitarget.h (FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION):
	Define.

2014-07-22  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	* doc/libffi.texi (Primitive Types): Document ffi_type_complex_float,
	ffi_type_complex_double and ffi_type_complex_longdouble
	(Complex Types): New subsection.
	(Complex Type Example): Ditto.
	* testsuite/libffi.call/cls_align_complex_double.c: New
	FFI_TYPE_COMPLEX test.
	* testsuite/libffi.call/cls_align_complex_float.c: Ditto.
	* testsuite/libffi.call/cls_align_complex_longdouble.c: Ditto.
	* testsuite/libffi.call/cls_complex_double.c: Ditto.
	* testsuite/libffi.call/cls_complex_float.c: Ditto.
	* testsuite/libffi.call/cls_complex_longdouble.c: Ditto.
	* testsuite/libffi.call/cls_complex_struct_double.c: Ditto.
	* testsuite/libffi.call/cls_complex_struct_float.c: Ditto.
	* testsuite/libffi.call/cls_complex_struct_longdouble.c: Ditto.
	* testsuite/libffi.call/cls_complex_va_double.c: Ditto.
	* testsuite/libffi.call/cls_complex_va_float.c: Ditto.
	* testsuite/libffi.call/cls_complex_va_longdouble.c: Ditto.
	* testsuite/libffi.call/complex_double.c: Ditto.
	* testsuite/libffi.call/complex_defs_double.c: Ditto.
	* testsuite/libffi.call/complex_float.c: Ditto.
	* testsuite/libffi.call/complex_defs_float.c: Ditto.
	* testsuite/libffi.call/complex_longdouble.c: Ditto.
	* testsuite/libffi.call/complex_defs_longdouble.c: Ditto.
	* testsuite/libffi.call/complex_int.c: Ditto.
	* testsuite/libffi.call/many_complex_double.c: Ditto.
	* testsuite/libffi.call/many_complex_float.c: Ditto.
	* testsuite/libffi.call/many_complex_longdouble.c: Ditto.
	* testsuite/libffi.call/return_complex1_double.c: Ditto.
	* testsuite/libffi.call/return_complex1_float.c: Ditto.
	* testsuite/libffi.call/return_complex1_longdouble.c: Ditto.
	* testsuite/libffi.call/return_complex2_double.c: Ditto.
	* testsuite/libffi.call/return_complex2_float.c: Ditto.
	* testsuite/libffi.call/return_complex2_longdouble.c: Ditto.
	* testsuite/libffi.call/return_complex_double.c: Ditto.
	* testsuite/libffi.call/return_complex_float.c: Ditto.
	* testsuite/libffi.call/return_complex_longdouble.c: Ditto.
	* src/raw_api.c (ffi_raw_to_ptrarray): Handle FFI_TYPE_COMPLEX
	(ffi_ptrarray_to_raw): Ditto.
	* src/prep_cif.c (ffi_prep_cif_core): Abort if FFI_TYPE_COMPLEX is not
	implemented in libffi for the target.
	* src/java_raw_api.c (ffi_java_raw_size): FFI_TYPE_COMPLEX not supported
	yet (abort).
	(ffi_java_raw_to_ptrarray): Ditto.
	(ffi_java_rvalue_to_raw): Ditto.
	(ffi_java_raw_to_rvalue):  Ditto.
	* src/debug.c (ffi_type_test): Add debug tests for complex types.
	* include/ffi.h.in (FFI_TYPE_COMPLEX): Add new FFI_TYPE_COMPLEX.
	(FFI_TYPE_LAST): Bump.
	(ffi_type_complex_float): Add new ffi_type_....
	(ffi_type_complex_double): Ditto.
	(ffi_type_complex_longdouble): Ditto.

2014-07-22  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	* src/s390/ffitarget.h (FFI_TARGET_HAS_COMPLEX_TYPE): Define to provide
	FFI_TYPE_COMPLEX support.
	* src/s390/ffi.c (ffi_check_struct_type): Implement FFI_TYPE_COMPLEX
	(ffi_prep_args): Ditto.
	(ffi_prep_cif_machdep): Ditto.
	(ffi_closure_helper_SYSV): Ditto.