thecl: Add support for th15

Issue #3
Two new instructions are found.
ID 546: SS
ID 549: S

Author: tirr-c

thecl10.c

@@ -800,6 +800,8 @@ static const id_format_pair_t th143_fmts[] = {
 };
 
 static const id_format_pair_t th15_fmts[] = {
+    { 546, "SS" },
+    { 549, "S" },
     { 569, "S" },
     { -1, NULL }
 };