patch 9.0.2050: Vim9: crash with deferred function call and exception

Problem:  Vim9: crash with deferred function call and exception
Solution: Save and restore exception state

Crash when a deferred function is called after an exception and another
exception is thrown

closes: #13376
closes: #13377

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>
diff --git a/src/testdir/test_user_func.vim b/src/testdir/test_user_func.vim
index 8fc82c4..8c3f33d 100644
--- a/src/testdir/test_user_func.vim
+++ b/src/testdir/test_user_func.vim
@@ -873,11 +873,21 @@
 " Test for calling a deferred function after an exception
 func Test_defer_after_exception()
   let g:callTrace = []
+  func Bar()
+    let g:callTrace += [1]
+    throw 'InnerException'
+  endfunc
+
   func Defer()
-    let g:callTrace += ['a']
-    let g:callTrace += ['b']
-    let g:callTrace += ['c']
-    let g:callTrace += ['d']
+    let g:callTrace += [2]
+    let g:callTrace += [3]
+    try
+      call Bar()
+    catch /InnerException/
+      let g:callTrace += [4]
+    endtry
+    let g:callTrace += [5]
+    let g:callTrace += [6]
   endfunc
 
   func Foo()
@@ -888,9 +898,9 @@
   try
     call Foo()
   catch /TestException/
-    let g:callTrace += ['e']
+    let g:callTrace += [7]
   endtry
-  call assert_equal(['a', 'b', 'c', 'd', 'e'], g:callTrace)
+  call assert_equal([2, 3, 1, 4, 5, 6, 7], g:callTrace)
 
   delfunc Defer
   delfunc Foo