patch 8.2.3303: some structures could be smaller

Problem:    Some structures could be smaller.
Solution:   Rearrange members to reduce size. (Dominique Pellé, closes #8725)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index f415d9a..19a7a8d 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -85,8 +85,8 @@
 
     garray_T	ec_trystack;	// stack of trycmd_T values
 
-    int		ec_dfunc_idx;	// current function index
     isn_T	*ec_instr;	// array with instructions
+    int		ec_dfunc_idx;	// current function index
     int		ec_iidx;	// index in ec_instr: instruction to execute
 
     garray_T	ec_funcrefs;	// partials that might be a closure