MSVC backtrace

vlib/compiler/cheaders.v

@@ -19,6 +19,9 @@ CommonCHeaders = '
 #include <sys/time.h>
 #include <unistd.h> // sleep
 #else
+#if defined(_MSC_VER)
+#pragma comment(lib, "Dbghelp.lib")
+#endif
 #if defined(__MSVCRT_VERSION__) && __MSVCRT_VERSION__ < __MSVCR90_DLL
 #error Please upgrade your MinGW distribution to use msvcr90.dll or later.
 #endif

vlib/compiler/msvc.v

@@ -3,7 +3,7 @@ module compiler
 import os
 
 #flag windows -l shell32
-
+#flag windows -l dbghelp
 // RegOpenKeyExA etc
 #flag windows -l advapi32
 

vlib/compiler/tests/backtrace_test.v

@@ -0,0 +1,11 @@
+/*
+ Test for backtrace capability
+*/
+fn a_method() {
+	print_backtrace() 
+}
+
+fn test_backtrace() {
+	a_method()
+	//panic('hi')
+}