target-xtensa: add FP registers

There are 16 32-bit FP registers (f0 - f15), control and status user
registers (fcr, fsr).

See ISA, 4.3.10 for more details.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/target-xtensa/helper.h b/target-xtensa/helper.h
index 152fec0..1662552 100644
--- a/target-xtensa/helper.h
+++ b/target-xtensa/helper.h
@@ -36,4 +36,6 @@
 DEF_HELPER_3(wsr_dbreaka, void, env, i32, i32)
 DEF_HELPER_3(wsr_dbreakc, void, env, i32, i32)
 
+DEF_HELPER_2(wur_fcr, void, env, i32)
+
 #include "def-helper.h"