patch 8.1.2081: the spell.c file is too big

Problem:    The spell.c file is too big.
Solution:   Move the code for spell suggestions to a separate file. (Yegappan
            Lakshmanan, closes #4988)
diff --git a/Filelist b/Filelist
index ff9d439..fa79344 100644
--- a/Filelist
+++ b/Filelist
@@ -111,6 +111,7 @@
 		src/spell.c \
 		src/spell.h \
 		src/spellfile.c \
+		src/spellsuggest.c \
 		src/structs.h \
 		src/syntax.c \
 		src/tag.c \
@@ -255,6 +256,7 @@
 		src/proto/sound.pro \
 		src/proto/spell.pro \
 		src/proto/spellfile.pro \
+		src/proto/spellsuggest.pro \
 		src/proto/syntax.pro \
 		src/proto/tag.pro \
 		src/proto/term.pro \