8139386: JVMCI test failed with assert(_jvmci._alternate_call_target == 0L) failed: must be

Reviewed-by: kvn
diff --git a/hotspot/src/cpu/sparc/vm/sharedRuntime_sparc.cpp b/hotspot/src/cpu/sparc/vm/sharedRuntime_sparc.cpp
index 8057453..902fa8f 100644
--- a/hotspot/src/cpu/sparc/vm/sharedRuntime_sparc.cpp
+++ b/hotspot/src/cpu/sparc/vm/sharedRuntime_sparc.cpp
@@ -1001,7 +1001,7 @@
     __ delayed()->nop();
 
     __ ld_ptr(G2_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset()), G3);
-    __ st(G0, Address(G2_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())));
+    __ st_ptr(G0, Address(G2_thread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())));
 
     __ bind(no_alternative_target);
   }