PPC: Fix GC barrier for TSETM.

src/buildvm_ppc.dasc

@@ -3924,7 +3924,7 @@ static void build_ins(BuildCtx *ctx, BCOp op, int defop)
     |  b <1
     |
     |7:  // Possible table write barrier for any value. Skip valiswhite check.
-    |  barrierback TAB:RB, TMP3, TMP0
+    |  barrierback TAB:CARG2, TMP3, TMP0
     |  b <4
     break;
 

src/buildvm_ppc.h

@@ -6646,11 +6646,11 @@ static const unsigned int build_actionlist[7562] = {
 0x80110000,
 0x00098200,
 0x54c607b8,
-0x91510000,
+0x90910000,
 0x00098200,
-0x98ca0000,
+0x98c40000,
 0x00098200,
-0x900a0000,
+0x90040000,
 0x00098200,
 0x00000000,
 0x48000000,