RFR(XS): 8146092: gcc 4.3: -fno-var-tracking-assignments not available

[Lindenmaier, Goetz]

Hi,

gcc 4.3 does not grok -fno-var-tracking-assignments.
I was told gcc 4.5 would known the flag, but I can not test that.
So I now check for >= 4.8.
It's only a note, so it should not matter to "warnings are errors".
I also remove a ia64 special case that's not necessary.

Please review. I please need a sponsor.
http://cr.openjdk.java.net/~goetz/webrevs/8146092-gcc4.3/webrev.00/

This is not urgent as fixes for gcc 4.1.2, as we don't use 4.3 in our
test builds or internal VM.

Best regards,
  Goetz.