Go patch committed: Avoid reading bogus field

[Ian Lance Taylor]

PR 59545 points out that there is a case where the Go frontend reads an
invalid value from a class field.  This happens because of an incorrect
static_cast.  This patch fixes the problem to only use the static_cast
when it is valid.  Bootstrapped and ran Go tests on
x86_64-unknown-linux-gnu.  Committed to mainline.

Ian

-------------- next part --------------
A non-text attachment was scrubbed...
Name: foo.patch
Type: text/x-diff
Size: 683 bytes
Desc: patch
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20140328/ff65a7f7/attachment.bin>