target/i386: Do not re-compute new pc with CF_PCREL

target/i386: Do not re-compute new pc with CF_PCREL

With PCREL, we have a page-relative view of EIP, and an
approximation of PC = EIP+CSBASE that is good enough to
detect page crossings.  If we try to recompute PC after
masking EIP, we will mess up that approximation and write
a corrupt value to EIP.

We already handled masking properly for PCREL, so the
fix in b5e0d5d2 was only needed for the !PCREL path.

Cc: qemu-stable@nongnu.org
Fixes: b5e0d5d22fbf ("target/i386: Fix 32-bit wrapping of pc/eip computation")
Fixes: 5b2fd6cf3735 (b5e0d5d22fbf in 8.1.4)
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240101230617.129349-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit a58506b748b8988a95f4fa1a2420ac5c17038b30)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>