patch 8.1.1195: Vim script debugger functionality needs cleanup

Problem:    Vim script debugger functionality needs cleanup.
Solution:   Move debugger code to a separate file.  Add more tests. (Yegappan
            Lakshmanan, closes #4285)
diff --git a/src/Make_manx.mak b/src/Make_manx.mak
index d150e4b..6eb7bfa 100644
--- a/src/Make_manx.mak
+++ b/src/Make_manx.mak
@@ -43,6 +43,7 @@
 	charset.c \
 	crypt.c \
 	crypt_zip.c \
+	debugger.c \
 	dict.c \
 	diff.c \
 	digraph.c \
@@ -105,6 +106,7 @@
 	obj/charset.o \
 	obj/crypt.o \
 	obj/crypt_zip.o \
+	obj/debugger.o \
 	obj/dict.o \
 	obj/diff.o \
 	obj/digraph.o \
@@ -165,6 +167,7 @@
 	proto/charset.pro \
 	proto/crypt.pro \
 	proto/crypt_zip.pro \
+	proto/debugger.pro \
 	proto/dict.pro \
 	proto/diff.pro \
 	proto/digraph.pro \
@@ -283,6 +286,9 @@
 obj/crypt_zip.o: crypt_zip.c
 	$(CCSYM) $@ crypt_zip.c
 
+obj/debugger.o:	debugger.c
+	$(CCSYM) $@ debugger.c
+
 obj/dict.o:	dict.c
 	$(CCSYM) $@ dict.c