target-i386: fix coding standards in x86_cpu_handle_mmu_fault

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: commonize checks for 2MB and 4KB pages

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: commonize checks for 4MB and 4KB pages

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: commonize checks for PAE and non-PAE

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: tweak handling of PG_NX_MASK

Remove the tail of the PAE case, so that we can use "goto" in the
next patch to jump to the protection checks.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: introduce do_check_protect label

This will help adding 1GB page support in the next patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target-i386: introduce support for 1 GB pages

Given the simplifications to the code in the previous pages, this
is now very simple to do.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>