revert r58478 and r58479 because they do not support not in-place build

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58480 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -712,7 +712,7 @@ test-rubyspec-precheck: $(arch)-fake.rb
 test-rubyspec: $(TEST_RUNNABLE)-test-rubyspec
 yes-test-rubyspec: test-rubyspec-precheck
 	$(gnumake_recursive)$(Q) \
-	$(RUNRUBY) -r./$(arch)-fake $(srcdir)/spec/mspec/bin/mspec run $(MSPECOPT)
+	$(RUNRUBY) -r./$(arch)-fake $(srcdir)/spec/mspec/bin/mspec run -B $(srcdir)/spec/default.mspec $(MSPECOPT)
 no-test-rubyspec: test-rubyspec-precheck
 
 RUNNABLE = $(LIBRUBY_RELATIVE:no=un)-runnable

spec/default.mspec

@@ -1,5 +1,5 @@
 # -*- ruby -*-
-require_relative "../rbconfig"
+load "./rbconfig.rb"
 load File.dirname(__FILE__) + '/rubyspec/default.mspec'
 OBJDIR = File.expand_path("spec/rubyspec/optional/capi/ext")
 class MSpecScript