Cygwin: Makefile: Drop all the "test dll" considerations

After 90236c3a2c, the testsuite is failing, as the cygwin0.dll
referenced by the implib that testsuite programs are linked with doesn't
exist anymore.

We don't need to make and link the testsuite with a specially named DLL,
as the cygwin DLL (since 526b0fbca3) takes into consideration the path
it's executing from to define separate "Cygwin installations", which
don't interact.

Fixes: 90236c3a2c ("Cygwin: Makefile: build new-cygwin1.dll in a single step")

winsup/cygwin/Makefile.am

@@ -43,7 +43,6 @@ DLL_NAME=cygwin1.dll
 NEW_DLL_NAME=new-cygwin1.dll
 DEF_FILE=cygwin.def
 LIB_NAME=libcygwin.a
-TEST_LIB_NAME=libcygwin0.a
 
 #
 # sources
@@ -618,10 +617,6 @@ LIBCOS=$(addsuffix .o,$(basename $(LIB_FILES)))
 $(LIB_NAME): $(DEF_FILE) $(LIBCOS) | $(NEW_DLL_NAME)
 	$(AM_V_GEN)$(srcdir)/scripts/mkimport $(toolopts) $(NEW_FUNCTIONS) $@ cygdll.a $(wordlist 2,99,$^)
 
-# cygwin import library used by testsuite
-$(TEST_LIB_NAME): $(LIB_NAME)
-	$(AM_V_GEN)perl -p -e 'BEGIN{binmode(STDIN); binmode(STDOUT);}; s/cygwin1/cygwin0/g' < $? > $@
-
 # sublibs
 # import libraries for some subset of symbols indicated by given objects
 speclib=\
@@ -664,7 +659,7 @@ libssp.a: $(LIB_NAME) $(wildcard $(newlib_build)/libc/ssp/*.o)
 # all
 #
 
-all-local: $(LIB_NAME) $(TEST_LIB_NAME) $(SUBLIBS)
+all-local: $(LIB_NAME) $(SUBLIBS)
 
 #
 # clean
@@ -675,7 +670,7 @@ clean-local:
 	-rm -f $(DEF_FILE) sigfe.s
 	-rm -f cygwin.sc cygdll.a cygwin.map
 	-rm -f $(NEW_DLL_NAME)
-	-rm -f $(LIB_NAME) $(TEST_LIB_NAME) $(SUBLIBS)
+	-rm -f $(LIB_NAME) $(SUBLIBS)
 	-rm -f version.cc
 	-rm -f tlsoffsets
 

winsup/testsuite/winsup.api/winsup.exp

@@ -61,7 +61,7 @@ foreach src [lsort [glob -nocomplain $srcdir/$subdir/*.c $srcdir/$subdir/*/*.{cc
     if [ file exists "$srcdir/$subdir/$basename.exp" ] then {
 	source "$srcdir/$subdir/$basename.exp"
     } else {
-	ws_spawn "$CC -nodefaultlibs -mwin32 $CFLAGS $src $add_includes $add_libs $runtime_root/binmode.o -lgcc $runtime_root/libcygwin0.a -lkernel32 -luser32 -o $base.exe"
+	ws_spawn "$CC -nodefaultlibs -mwin32 $CFLAGS $src $add_includes $add_libs $runtime_root/binmode.o -lgcc $runtime_root/libcygwin.a -lkernel32 -luser32 -o $base.exe"
 	if { $rv } {
 	    fail "$testcase (compile)"
 	} else {