Merge branch 'js/mingw-open-in-gdb'

Dev support.

* js/mingw-open-in-gdb:
  mingw: add a helper function to attach GDB to the current process

compat/mingw.h

@@ -598,6 +598,16 @@ extern CRITICAL_SECTION pinfo_cs;
 int wmain(int argc, const wchar_t **w_argv);
 int main(int argc, const char **argv);
 
+/*
+ * For debugging: if a problem occurs, say, in a Git process that is spawned
+ * from another Git process which in turn is spawned from yet another Git
+ * process, it can be quite daunting to figure out what is going on.
+ *
+ * Call this function to open a new MinTTY (this assumes you are in Git for
+ * Windows' SDK) with a GDB that attaches to the current process right away.
+ */
+extern void open_in_gdb(void);
+
 /*
  * Used by Pthread API implementation for Windows
  */