Fix rubyspec_capiext dependency and flags

- The file needed to link may be the import library.
- Remove duplicate flags.

defs/gmake.mk

@@ -404,10 +404,10 @@ update-deps:
 
 # order-only-prerequisites doesn't work for $(RUBYSPEC_CAPIEXT)
 # because the same named directory exists in the source tree.
-$(RUBYSPEC_CAPIEXT)/%.$(DLEXT): $(srcdir)/$(RUBYSPEC_CAPIEXT)/%.c $(srcdir)/$(RUBYSPEC_CAPIEXT)/rubyspec.h $(RUBY_H_INCLUDES) $(LIBRUBY_SO)
+$(RUBYSPEC_CAPIEXT)/%.$(DLEXT): $(srcdir)/$(RUBYSPEC_CAPIEXT)/%.c $(srcdir)/$(RUBYSPEC_CAPIEXT)/rubyspec.h $(RUBY_H_INCLUDES) $(LIBRUBY)
 	$(ECHO) building $@
 	$(Q) $(MAKEDIRS) $(@D)
-	$(Q) $(DLDSHARED) $(XDLDFLAGS) $(XLDFLAGS) $(ARCH_FLAG) $(ARCH_FLAG) $(CFLAGS) $(INCFLAGS) $(CPPFLAGS) $(OUTFLAG)$@ $< $(LIBRUBY_SO)
+	$(Q) $(DLDSHARED) $(XDLDFLAGS) $(XLDFLAGS) $(LDFLAGS) $(INCFLAGS) $(CPPFLAGS) $(OUTFLAG)$@ $< $(LIBRUBYARG)
 	$(Q) $(RMALL) $@.*
 
 rubyspec-capiext: $(patsubst %.c,$(RUBYSPEC_CAPIEXT)/%.$(DLEXT),$(notdir $(wildcard $(srcdir)/$(RUBYSPEC_CAPIEXT)/*.c)))

spec/ruby/optional/capi/spec_helper.rb

@@ -32,9 +32,8 @@ def compile_extension(name)
   ruby_header = "#{RbConfig::CONFIG['rubyhdrdir']}/ruby.h"
 
   if RbConfig::CONFIG["ENABLE_SHARED"] == "yes"
-    libdirname = RbConfig::CONFIG['LIBPATHENV'] == 'PATH' ? 'bindir' :
-                   RbConfig::CONFIG['libdirname'] # defined since 2.1
-    libruby_so = "#{RbConfig::CONFIG[libdirname]}/#{RbConfig::CONFIG['LIBRUBY_SO']}"
+    libdirname = RbConfig::CONFIG['libdirname'] # defined since 2.1
+    libruby = "#{RbConfig::CONFIG[libdirname]}/#{RbConfig::CONFIG['LIBRUBY']}"
   end
 
   begin
@@ -46,7 +45,7 @@ def compile_extension(name)
     when mtime <= File.mtime("#{core_ext_dir}/rubyspec.h")
     when mtime <= File.mtime("#{spec_ext_dir}/#{ext}.c")
     when mtime <= File.mtime(ruby_header)
-    when libruby_so && mtime <= File.mtime(libruby_so)
+    when libruby && mtime <= File.mtime(libruby)
     else
       return lib # up-to-date
     end