target-i386: Wrong conversion infinity from float80 to int32/int64

Signed-off-by: Dmitry Poletaev <poletaev-qemu@yandex.ru>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: fbld instruction doesn't set minus sign

Signed-off-by: Dmitry Poletaev <poletaev-qemu@yandex.ru>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: fix icount processing for repz instructions

TCG generates optimized code for i386 repz instructions in single step mode.
It means that when ecx becomes 0, execution of the string instruction breaks
immediately without an additional iteration for ecx==0 (which will only check
ecx and set the flags). Omitting this iteration leads to different
instructions counting in singlestep mode and in normal execution.
This patch disables optimization of this last iteration for icount mode
which should be deterministic.

v2: inverted the condition and formatted the comment

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Merge remote-tracking branch 'remotes/rth/tags/x86-next-20141214' into staging

Collected x86 patches

# gpg: Signature made Sun 14 Dec 2014 22:54:28 GMT using RSA key ID 4DD0279B
# gpg: Good signature from "Richard Henderson <rth7680@gmail.com>"
# gpg:                 aka "Richard Henderson <rth@redhat.com>"
# gpg:                 aka "Richard Henderson <rth@twiddle.net>"

* remotes/rth/tags/x86-next-20141214:
  target-i386: fix icount processing for repz instructions
  target-i386: fbld instruction doesn't set minus sign
  target-i386: Wrong conversion infinity from float80 to int32/int64

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>