Rename DOS-created uppercase *.FB files to lowercase, with corresponding

Makefile changes.

8086/msdos/Makefile

@@ -1,23 +1,33 @@
 
-test: logtest.result
+fbfiles = $(wildcard src/*.fb tests/*.fb)
+fthfiles = $(patsubst %.fb, %.fth, $(fbfiles))
+
+fbfiles_uppercase = $(wildcard src/*.FB tests/*.FB)
+fthfiles_caseconverted = $(patsubst %.fb, %.fth, \
+    $(shell ../../tools/echo-tolower.py $(fbfiles_uppercase)))
+
+test: incltest.result logtest.result
+
+fth: $(fthfiles) $(fthfiles_caseconverted)
 
 clean:
 	rm -f *.log *.LOG *.result *.golden
 
-v4thfile.com: volks4th.com  src/V4THFILE.FB \
+
+v4thfile.com: volks4th.com  src/include.fb src/v4thfile.fb \
     emulator/run-in-dosbox.sh
 	rm -f V4THFILE.COM v4thfile.com
 	./emulator/run-in-dosbox.sh volks4th.com v4thfile.fb
 	mv V4THFILE.COM v4thfile.com
 
-incltest.log: v4thfile.com tests/LOG2FILE.FB tests/incltest.fth \
+incltest.log: v4thfile.com tests/log2file.fb tests/incltest.fth \
     emulator/run-in-dosbox.sh
 	./emulator/run-in-dosbox.sh v4thfile.com incltest.fth
 
 incltest.golden: tests/golden/incltest.golden
 	cp -p $< $@
 
-logtest.log: volks4th.com tests/LOG2FILE.FB tests/LOGTEST.FB \
+logtest.log: volks4th.com tests/log2file.fb tests/logtest.fb \
     emulator/run-in-dosbox.sh
 	./emulator/run-in-dosbox.sh volks4th.com logtest.fb
 
@@ -34,11 +44,10 @@ src/%.fth: src/%.fb ../../tools/fb2fth.py
 tests/%.fth: tests/%.fb ../../tools/fb2fth.py
 	../../tools/fb2fth.py $< $@
 
-fbfiles = $(wildcard src/*.FB tests/*.FB)
-fthfiles = $(patsubst %.fb, %.fth, \
-    $(shell ../../tools/echo-tolower.py $(fbfiles)))
-
-fth: $(fthfiles)
+# Collective rule for converting uppercase *.FB to lowercase *.fth.
+# Because make doesn't provide case changing pattern matching,
+# file-by-file dependencies as with the src/%.fth and tests/%.fth
+# rules doesn't seem feasible here, hence the one collective rule.
 
 .ONESHELL:
 $(fthfiles): $(fbfiles)