cd to the physical source directory for symlinked build directory

Author: nobu

configure.ac

@@ -4703,7 +4703,7 @@ AC_CONFIG_FILES(Makefile:template/Makefile.in, [
 	    echo common_mk_includes "@S|@*" # generate the macro assignment
 	    shift
 	    common_mk_includes="`echo \"@S|@*\" | sed 's|\$(srcdir)|.|g'`"
-	    (cd ${srcdir} && sed -f tool/prereq.status common.mk ${common_mk_includes})
+	    ($CHDIR ${srcdir} && sed -f tool/prereq.status common.mk ${common_mk_includes})
             AS_IF([test "$YJIT_SUPPORT" = yes], [
                 cat ${srcdir}/yjit/not_gmake.mk
                 echo ['$(MKFILES): ${srcdir}/yjit/not_gmake.mk']
@@ -4729,7 +4729,7 @@ AC_CONFIG_FILES(Makefile:template/Makefile.in, [
 	rm -f uncommon.mk # remove stale uncommon.mk, it should be updated by GNUmakefile
 	test "$tmpmk" = "$tmpgmk" || rm -f "$tmpgmk"
     ]) && mv -f $tmpmk Makefile],
-[EXEEXT='$EXEEXT' MAKE='${MAKE-make}' gnumake='$gnumake' GIT='$GIT' YJIT_SUPPORT='$YJIT_SUPPORT'])
+[CHDIR='$CHDIR' EXEEXT='$EXEEXT' MAKE='${MAKE-make}' gnumake='$gnumake' GIT='$GIT' YJIT_SUPPORT='$YJIT_SUPPORT'])
 
 AC_ARG_WITH([ruby-pc],
 	    AS_HELP_STRING([--with-ruby-pc=FILENAME], [pc file basename]),