configure.ac: use BASERUBY as BOOTSTRAPRUBY if available

MINIRUBY may not be stable enough to run btest, in developing.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66859 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.ac

@@ -3016,6 +3016,7 @@ for var in bindir libdir rubylibprefix; do
 done
 
 BTESTRUBY='$(MINIRUBY)'
+BOOTSTRAPRUBY='$(BASERUBY)'
 AS_IF([test x"$cross_compiling" = xyes], [
   test x"$MINIRUBY" = x && MINIRUBY="${RUBY-$BASERUBY} -I`$CHDIR .; pwd` "-r'$(arch)-fake'
   XRUBY_LIBDIR=`${RUBY-$BASERUBY} -rrbconfig -e ['puts RbConfig::CONFIG["libdir"]']`
@@ -3028,7 +3029,6 @@ AS_IF([test x"$cross_compiling" = xyes], [
   RUNRUBY_COMMAND='$(MINIRUBY) -I`cd $(srcdir)/lib; pwd`'
   RUNRUBY='$(RUNRUBY_COMMAND)'
   XRUBY='$(MINIRUBY)'
-  BOOTSTRAPRUBY='$(BASERUBY)'
   TEST_RUNNABLE=no
   CROSS_COMPILING=yes
 ], [
@@ -3038,7 +3038,7 @@ AS_IF([test x"$cross_compiling" = xyes], [
   RUNRUBY_COMMAND='$(MINIRUBY) $(srcdir)/tool/runruby.rb --extout=$(EXTOUT) $(RUNRUBYOPT)'
   RUNRUBY='$(RUNRUBY_COMMAND) --'
   XRUBY='$(RUNRUBY)'
-  BOOTSTRAPRUBY='$(MINIRUBY)'
+  test "$HAVE_BASERUBY" = yes || BOOTSTRAPRUBY='$(MINIRUBY)'
   TEST_RUNNABLE=yes
   CROSS_COMPILING=no
 ])