8023287: HOTSPOT_BUILD_COMPILER needs to support "Sun Studio 12u3"

Summary: Recognize 0x5120 as "Sun Studio 12u3".
Reviewed-by: dholmes, coleenp

src/share/vm/runtime/vm_version.cpp

@@ -231,6 +231,8 @@ const char* Abstract_VM_Version::internal_vm_info_string() {
         #define HOTSPOT_BUILD_COMPILER "Workshop 5.9"
       #elif __SUNPRO_CC == 0x5100
         #define HOTSPOT_BUILD_COMPILER "Sun Studio 12u1"
+      #elif __SUNPRO_CC == 0x5120
+        #define HOTSPOT_BUILD_COMPILER "Sun Studio 12u3"
       #else
         #define HOTSPOT_BUILD_COMPILER "unknown Workshop:" XSTR(__SUNPRO_CC)
       #endif