testsuite: find files when building in remote directory

* doc/Makefile.am, src/ltltest/defs.in, src/ltltest/latex.test: Here.

doc/Makefile.am

@@ -51,9 +51,9 @@ dist_pkgdata_DATA = $(srcdir)/spot.tag
 
 .PHONY: org
 org:
-	cd $(top_srcdir) && make doc/org/init.el
+	cd $(top_builddir) && make doc/org/init.el
 	rm -rf $(srcdir)/userdoc; mkdir -p tmp; cd tmp; \
-	$(EMACS) --batch -Q -l $(abs_srcdir)/org/init.el
+	$(EMACS) --batch -Q -l ../org/init.el
 	rm -rf tmp
 
 ORG_FILES = \

src/ltltest/defs.in

@@ -51,6 +51,7 @@ cd $testSubDir
 
 DOT='@DOT@'
 VALGRIND='@VALGRIND@'
+top_srcdir='../@top_srcdir@'
 
 run()
 {

src/ltltest/latex.test

@@ -55,7 +55,7 @@ cat <<\EOF
 EOF
 ) > output.tex
 
-TEXINPUTS=$srcdir/../../../doc/tl: \
+TEXINPUTS=$top_srcdir/doc/tl: \
 latexmk -f -silent -pdf -ps- -dvi- -pvc- output.tex
 
 # latexmk will have a non-zero exit status on failure, so we will