some javadoc tests may contain false positive results

When checking negative tests, JavadocTester may give a false positive if the text could not be found because the file did not exist. The following is a list of results to check out, where the .jtr file has a line containing FileNotFoundException. These cases all need to be checked out to see if the exception is part of the intended behavior of the test.

Related, JavadocTester should probably *fail* a negative test if the file does not exist.

$ find build/jtreg/work -name \*.jtr | xargs -n 1 grep --with-filename FileNotFoundException
build/jtreg/work/com/sun/javadoc/testDocFileDir/TestDocFileDir.jtr:java.io.FileNotFoundException: 4258405-4973606-2/pkg/doc-files/subdir-excluded1/testfile.txt (No such file or directory)
build/jtreg/work/com/sun/javadoc/testDocFileDir/TestDocFileDir.jtr:java.io.FileNotFoundException: 4258405-4973606-2/pkg/doc-files/subdir-excluded2/testfile.txt (No such file or directory)
build/jtreg/work/com/sun/javadoc/testEncoding/TestEncoding.jtr:java.io.FileNotFoundException: 4661481/EncodeTest.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testProfiles/TestProfiles.jtr:java.io.FileNotFoundException: 8006124-8009684-8016921-2/profile-overview-frame.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testProfiles/TestProfiles.jtr:java.io.FileNotFoundException: 8006124-8009684-8016921-2/compact2-frame.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testProfiles/TestProfiles.jtr:java.io.FileNotFoundException: 8006124-8009684-8016921-2/pkg2/compact2-package-frame.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testProfiles/TestProfiles.jtr:java.io.FileNotFoundException: 8006124-8009684-8016921-2/compact2-summary.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testProfiles/TestProfiles.jtr:java.io.FileNotFoundException: 8006124-8009684-8016921-2/pkg5/compact3-package-summary.html (No such file or directory)
build/jtreg/work/com/sun/javadoc/testMethodTypes/TestMethodTypes.jtr:java.io.FileNotFoundException: 8002304/pkg/D.html (No such file or directory)