ci: fix vlib/dl/example/use_test.v in windows-tcc

vlib/builtin/builtin_windows.c.v

@@ -1,12 +1,11 @@
 // Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
 // Use of this source code is governed by an MIT license
 // that can be found in the LICENSE file.
-
 module builtin
 
 // dbghelp.h is already included in cheaders.v
 #flag windows -l dbghelp
-
+// SymbolInfo is used by print_backtrace_skipping_top_frames_msvc
 pub struct SymbolInfo {
 pub mut:
 	f_size_of_struct u32 // must be 88 to be recognised by SymFromAddr
@@ -41,11 +40,18 @@ pub mut:
 	f_address        u64
 }
 
-fn C.SymSetOptions(symoptions u32) u32 // returns the current options mask
-fn C.GetCurrentProcess() voidptr // returns handle
+// returns the current options mask
+fn C.SymSetOptions(symoptions u32) u32
+
+// returns handle
+fn C.GetCurrentProcess() voidptr
+
 fn C.SymInitialize(h_process voidptr, p_user_search_path byteptr, b_invade_process int) int
+
 fn C.CaptureStackBackTrace(frames_to_skip u32, frames_to_capture u32, p_backtrace voidptr, p_backtrace_hash voidptr) u16
+
 fn C.SymFromAddr(h_process voidptr, address u64, p_displacement voidptr, p_symbol voidptr) int
+
 fn C.SymGetLineFromAddr64(h_process voidptr, address u64, p_displacement voidptr, p_line &Line64) int
 
 // Ref - https://docs.microsoft.com/en-us/windows/win32/api/dbghelp/nf-dbghelp-symsetoptions
@@ -61,9 +67,12 @@ const (
 
 // g_original_codepage - used to restore the original windows console code page when exiting
 __global ( g_original_codepage = u32(0))
+
 // utf8 to stdout needs C.SetConsoleOutputCP(C.CP_UTF8)
 fn C.GetConsoleOutputCP() u32
+
 fn C.SetConsoleOutputCP(wCodePageID u32) bool
+
 fn restore_codepage() {
 	C.SetConsoleOutputCP(g_original_codepage)
 }
@@ -110,7 +119,9 @@ $if msvc {
 		sline64.f_size_of_struct = sizeof(Line64)
 
 		handle := C.GetCurrentProcess()
-	defer { C.SymCleanup(handle) }
+		defer {
+			C.SymCleanup(handle)
+		}
 
 		C.SymSetOptions(symopt_debug | symopt_load_lines | symopt_undname)
 
@@ -132,7 +143,8 @@ $if msvc {
 				mut lineinfo := ''
 				if C.SymGetLineFromAddr64(handle, frame_addr, &offset, &sline64) == 1 {
 					file_name := tos3(sline64.f_file_name)
-				lineinfo = '${file_name}:${sline64.f_line_number}'
+					lnumber := sline64.f_line_number
+					lineinfo = '$file_name:$lnumber'
 				} else {
 					addr:
 					lineinfo = '?? : address = 0x${(&frame_addr):x}'
@@ -165,10 +177,15 @@ fn print_backtrace_skipping_top_frames_mingw(skipframes int) bool {
 }
 
 fn C.tcc_backtrace(fmt charptr, other ...charptr) int
+
 fn print_backtrace_skipping_top_frames_tcc(skipframes int) bool {
 	$if tinyc {
-		C.tcc_backtrace("Backtrace")
+		$if no_backtrace ? {
+			eprintln('backtraces are disabled')
+		} $else {
+			C.tcc_backtrace('Backtrace')
 			return false
+		}
 	} $else {
 		eprintln('print_backtrace_skipping_top_frames_tcc must be called only when the compiler is tcc')
 		return false
@@ -182,7 +199,6 @@ pub:
 	// status_ constants
 	code        u32
 	flags       u32
-
 	record      &ExceptionRecord
 	address     voidptr
 	param_count u32
@@ -202,6 +218,7 @@ pub:
 type VectoredExceptionHandler = fn (&ExceptionPointers) int
 
 fn C.AddVectoredExceptionHandler(int, C.PVECTORED_EXCEPTION_HANDLER)
+
 fn add_vectored_exception_handler(handler VectoredExceptionHandler) {
 	C.AddVectoredExceptionHandler(1, C.PVECTORED_EXCEPTION_HANDLER(handler))
 }
@@ -228,6 +245,7 @@ fn add_unhandled_exception_handler() {
 }
 
 fn C.IsDebuggerPresent() bool
+
 fn C.__debugbreak()
 
 fn break_if_debugger_attached() {