Add support for specifying child process cwd and env to wxExecute().

Add an optional wxExecuteEnv parameter to wxExecute() which allows to specify
the initial working directory and custom environment for the child process.

Closes #12163.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65896 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/os2/utilsexc.cpp

@@ -128,7 +128,8 @@ MRESULT APIENTRY wxExecuteWindowCbk( HWND   hWnd,
 
 long wxExecute( const wxString& rCommand,
                 int flags,
-                wxProcess* pHandler)
+                wxProcess* pHandler,
+                const wxExecuteEnv *env)
 {
     if (rCommand.empty())
     {
@@ -219,6 +220,7 @@ long wxExecute(
   char**                            ppArgv
 , int                               flags
 , wxProcess*                        pHandler
+, const wxExecuteEnv *env
 )
 {
     wxString                        sCommand;
@@ -234,6 +236,7 @@ long wxExecute(
     return wxExecute( sCommand
                      ,flags
                      ,pHandler
+                     , env
                     );
 }