gdb_main: Modify halt-responses to report thread p1.1 not 1 (regression since v1.10.0-1548-g 1a9fc96)

* GDB 10 through 12 works fine with T05 but generates bogus inferior 2 with T05thread:1;
* This form (T05thread:p1.1;) seems to fix that but it breaks again with run/vKill-packet (even for GDB-13 and newer)

Author: ALTracer

src/gdb_main.c

@@ -688,7 +688,7 @@ static void exec_v_attach(const char *const packet, const size_t length)
 			 * https://sourceware.org/pipermail/gdb-patches/2022-April/188058.html
 			 * https://sourceware.org/pipermail/gdb-patches/2022-July/190869.html
 			 */
-			gdb_putpacket_str_f("T%02Xthread:1;", GDB_SIGTRAP);
+			gdb_putpacket_str_f("T%02Xthread:p1.1;", GDB_SIGTRAP);
 		} else
 			gdb_put_packet_error(1U);
 
@@ -981,16 +981,16 @@ void gdb_poll_target(void)
 		morse("TARGET LOST.", true);
 		break;
 	case TARGET_HALT_REQUEST:
-		gdb_putpacket_str_f("T%02Xthread:1;", GDB_SIGINT);
+		gdb_putpacket_str_f("T%02Xthread:p1.1;", GDB_SIGINT);
 		break;
 	case TARGET_HALT_WATCHPOINT:
 		gdb_putpacket_str_f(
 			"T%02Xwatch:%0" PRIX32 "%08" PRIX32 ";", GDB_SIGTRAP, (uint32_t)(watch >> 32U), (uint32_t)watch);
 		break;
 	case TARGET_HALT_FAULT:
-		gdb_putpacket_str_f("T%02Xthread:1;", GDB_SIGSEGV);
+		gdb_putpacket_str_f("T%02Xthread:p1.1;", GDB_SIGSEGV);
 		break;
 	default:
-		gdb_putpacket_str_f("T%02Xthread:1;", GDB_SIGTRAP);
+		gdb_putpacket_str_f("T%02Xthread:p1.1;", GDB_SIGTRAP);
 	}
 }