target-ppc: Define FPR Pointer Type for Helpers

Define a floating pointer register pointer type in the PowerPC
helper header.  The type will be used to pass FPR register operands
to Decimal Floating Point (DFP) helpers.  A pointer is used because
the quad word forms of PowerPC DFP instructions operate on adjacent
pairs of floating point registers and thus can be thought of as
arrays of length 2.
Signed-off-by: NTom Musta <tommusta@gmail.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/helper.h

@@ -611,3 +611,7 @@ DEF_HELPER_3(store_dbatu, void, env, i32, tl)
 DEF_HELPER_3(store_601_batl, void, env, i32, tl)
 DEF_HELPER_3(store_601_batu, void, env, i32, tl)
 #endif
+
+#define dh_alias_fprp ptr
+#define dh_ctype_fprp uint64_t *
+#define dh_is_signed_fprp dh_is_signed_ptr