MFC 262999
Fixed MSI interrupt allocation and handling.
Fixed a DMA mapping leak that occurs when defragmenting packet chains.

Approved by:	davidch (mentor)
Turn off warnings for building aicasm.  Various versions of yacc exist,
which can result in different warnings-as-errors in this tool, but these
are all completely harmless.

This is a direct commit to stable/7, stable/8, stable/9 and stable/10,
since this kernel build tool has already been removed in head.