target/ppc: implement complete set of Vsr* macros

This prepares us for eliminating the use of direct array access within the VMX
instruction implementations.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

target/ppc/internal.h

@@ -206,16 +206,23 @@ EXTRACT_HELPER_SPLIT_3(DCMX_XV, 5, 16, 0, 1, 2, 5, 1, 6, 6);
 
 #if defined(HOST_WORDS_BIGENDIAN)
 #define VsrB(i) u8[i]
+#define VsrSB(i) s8[i]
 #define VsrH(i) u16[i]
+#define VsrSH(i) s16[i]
 #define VsrW(i) u32[i]
+#define VsrSW(i) s32[i]
 #define VsrD(i) u64[i]
+#define VsrSD(i) s64[i]
 #else
 #define VsrB(i) u8[15 - (i)]
+#define VsrSB(i) s8[15 - (i)]
 #define VsrH(i) u16[7 - (i)]
+#define VsrSH(i) s16[7 - (i)]
 #define VsrW(i) u32[3 - (i)]
+#define VsrSW(i) s32[3 - (i)]
 #define VsrD(i) u64[1 - (i)]
+#define VsrSD(i) s64[1 - (i)]
 #endif
-
 static inline void getVSR(int n, ppc_vsr_t *vsr, CPUPPCState *env)
 {
     vsr->VsrD(0) = env->vsr[n].u64[0];