x86/emul: Rename hvm_trap to x86_event and move it into the emulation infrastructure

x86/emul: Rename hvm_trap to x86_event and move it into the emulation infrastructure

The x86 emulator needs to gain an understanding of interrupts and exceptions
generated by its actions.  The naming choice is to match both the Intel and
AMD terms, and to avoid 'trap' specifically as it has an architectural meaning
different to its current usage.

While making this change, make other changes for consistency

 * Rename *_trap() infrastructure to *_event()
 * Rename trapnr/trap parameters to vector
 * Convert hvm_inject_hw_exception() and hvm_inject_page_fault() to being
   static inlines, as they are only thin wrappers around hvm_inject_event()

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>