[11] RFR(S): 8206998: [test] runtime/ElfDecoder/TestElfDirectRead.java requires longer timeout on ppc64

[Volker Simonis]

Hi,

can I please get a review for the following test-only change:

http://cr.openjdk.java.net/~simonis/webrevs/2018/8206998/
https://bugs.openjdk.java.net/browse/JDK-8206998

The problem is that the test runtime/ElfDecoder/TestElfDirectRead.java
intentionally disables caching of Elf sections during symbol lookup
with WhiteBox.disableElfSectionCache(). On platforms which do not use
file descriptors instead of plain function pointers this slows down
the lookup just a little bit, because all the symbols from an Elf file
are still read consecutively after one 'fseek()' call. But on
platforms with file descriptors like ppc64 big-endian, we get two
'fseek()' calls for each symbol read from the Elf file because reading
the file descriptor table is nested inside the loop which reads the
symbols. This really trashes the I/O system and considerable slows
down the test, so we need an extra long timeout setting.

The fix is trivial - simply provide two test versions (i.e. comments):
the first one for all Linux flavors which are not ppc64 and a second,
new one for Linux/ppc64 which simply has a bigger timeout.

Thank you and best regards,
Volker