patch 8.1.1076: file for Insert mode is much too big

Problem:    File for Insert mode is much too big.
Solution:   Split off the code for Insert completion. (Yegappan Lakshmanan,
            closes #4044)
diff --git a/src/spell.c b/src/spell.c
index 8aadb99..a778896 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -8473,7 +8473,7 @@
 	    arridx[0] = 0;
 	    curi[0] = 1;
 	    while (depth >= 0 && !got_int
-				       && (pat == NULL || !compl_interrupted))
+				  && (pat == NULL || !ins_compl_interrupted()))
 	    {
 		if (curi[depth] > byts[arridx[depth]])
 		{