Move wxEventLoopManual::m_shouldExit to wxEventLoopBase.

No real changes, just make this flag available to the other event loop
implementations as they will need it soon.

See #10258.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74332 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/evtloopcmn.cpp

@@ -30,6 +30,8 @@ wxEventLoopBase *wxEventLoopBase::ms_activeLoop = NULL;
 
 wxEventLoopBase::wxEventLoopBase()
 {
+    m_shouldExit = false;
+
     m_isInsideYield = false;
     m_eventsToProcessInsideYield = wxEVT_CATEGORY_ALL;
 }
@@ -91,7 +93,6 @@ bool wxEventLoopBase::Yield(bool onlyIfNeeded)
 wxEventLoopManual::wxEventLoopManual()
 {
     m_exitcode = 0;
-    m_shouldExit = false;
 }
 
 bool wxEventLoopManual::ProcessEvents()