RFR: 8065648: Remove the flag -fsanitize=undefined for GCC 4.9 and later

[Erik Helin]

Hi all,

this patch removes the usage of the flag -fsanitize=undefined introduced
in GCC 4.9. The reason for not using this flag is that the implementation
in GCC still seem to have some bugs [0] (which I have encountered). The
flag is currently only enabled for slowdebug builds.

My suggestion is that we remove the flag for now, since the only supported
GCC version is 4.8.2 [1]. Then we can revisit this decisision when we upgrade
the supported compiler to GCC 4.9.x, since hopefully the bugs in GCC have
been fixed by then.

What do you think?

Webrev:
http://cr.openjdk.java.net/~ehelin/8065648/webrev.00/

Bug:
https://bugs.openjdk.java.net/browse/JDK-8065648

Testing:
- Verified that generated-configure.sh no longer tries to enable the flag.

Thanks,
Erik

[0]: https://bugzilla.redhat.com/show_bug.cgi?id=1166173
[1]: http://mail.openjdk.java.net/pipermail/jdk9-dev/2014-October/001489.html