target-arm: A64: Add floating-point<->fixed-point instructions

This patch adds emulation for the instruction group labeled
"Floating-point <-> fixed-point conversions" in the ARM ARM.

Namely this includes the instructions SCVTF, UCVTF, FCVTZS, FCVTZU
(scalar, fixed-point).

Signed-off-by: Alexander Graf <agraf@suse.de>
[WN: Commit message tweak, rebased, updated to new infrastructure.
 Applied bug fixes from Michael Matz and Janne Grunau.]
Signed-off-by: Will Newton <will.newton@linaro.org>
[PMM: significant cleanup]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 2e1af46..25b6b4f 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -148,6 +148,8 @@
 DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr)
 DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr)
 
+DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, env)
+
 DEF_HELPER_2(vfp_fcvt_f16_to_f32, f32, i32, env)
 DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env)
 DEF_HELPER_2(neon_fcvt_f16_to_f32, f32, i32, env)