target-mips: fix page fault address for LWL/LWR/LDL/LDR

target-mips: fix page fault address for LWL/LWR/LDL/LDR

When a LWL, LWR, LDL or LDR instruction triggers a page fault, QEMU
currently reports the aligned address in CP0 BadVAddr, while the Windows
NT kernel expects the unaligned address.

This patch adds a byte access with the unaligned address at the
beginning of the LWL/LWR/LDL/LDR instructions to possibly trigger a page
fault and fill the QEMU TLB.

Cc: Leon Alrae <leon.alrae@imgtec.com>
Reported-by: Hervé Poussineau <hpoussin@reactos.org>
Tested-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>