dejagnu handlig fails if {build,host,target}_ailas is not defined

[Miloslav Trmac]

Hello,
dejagnu support assumes build_alias and others are defined, but they're
empty when nothing was given on the command line. In this case, the
site.exp file contains `set build_alias' and similar invalid lines.
This should fix it.
        Mirek

--- dejagnu.am.orig     Sat May 11 22:16:17 2002
+++ dejagnu.am  Sat May 11 22:17:58 2002
@@ -82,11 +82,11 @@
        @echo 'set tool $(DEJATOOL)' >>site.tmp
        @echo 'set srcdir $(srcdir)' >>site.tmp
        @echo "set objdir `pwd`" >>site.tmp
-?BUILD?        @echo 'set build_alias $(build_alias)' >>site.tmp
+?BUILD?        @echo 'set build_alias "$(build_alias)"' >>site.tmp
 ?BUILD?        @echo 'set build_triplet $(build_triplet)' >>site.tmp
-?HOST? @echo 'set host_alias $(host_alias)' >>site.tmp
+?HOST? @echo 'set host_alias "$(host_alias)"' >>site.tmp
 ?HOST? @echo 'set host_triplet $(host_triplet)' >>site.tmp
-?TARGET?       @echo 'set target_alias $(target_alias)' >>site.tmp
+?TARGET?       @echo 'set target_alias "$(target_alias)"' >>site.tmp
 ?TARGET?       @echo 'set target_triplet $(target_triplet)' >>site.tmp
        @echo '## All variables above are generated by configure. Do Not Edit 
##' >>site.tmp
        @test ! -f site.exp || \