libpanic_unwind: UNWIND_DATA_REG for sparc64

Author: jakllsch

src/libpanic_unwind/gcc.rs

@@ -133,6 +133,9 @@ const UNWIND_DATA_REG: (i32, i32) = (3, 4); // R3, R4 / X3, X4
 #[cfg(target_arch = "s390x")]
 const UNWIND_DATA_REG: (i32, i32) = (6, 7); // R6, R7
 
+#[cfg(target_arch = "sparc64")]
+const UNWIND_DATA_REG: (i32, i32) = (24, 25); // I0, I1
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c