Bug 1080108 - don't redefine STATUS_FLOAT_* values in nsSigHandlers.cpp; r=bsmedberg

Including <windows.h> picks these up, as recent builds indicate by warning:

c:\builds\moz2_slave\m-in-w32-000000000000000000000\build\toolkit\xre\nsSigHandlers.cpp(341) : warning C4005: 'STATUS_FLOAT_MULTIPLE_FAULTS' : macro redefinition
        c:\Program Files (x86)\Windows Kits\8.0\include\um\winnt.h(2127) : see previous definition of 'STATUS_FLOAT_MULTIPLE_FAULTS'
c:\builds\moz2_slave\m-in-w32-000000000000000000000\build\toolkit\xre\nsSigHandlers.cpp(342) : warning C4005: 'STATUS_FLOAT_MULTIPLE_TRAPS' : macro redefinition
        c:\Program Files (x86)\Windows Kits\8.0\include\um\winnt.h(2128) : see previous definition of 'STATUS_FLOAT_MULTIPLE_TRAPS'
Bug 1080107 - remove XPI_NAME definitions from crashreporter moz.build files; r=mshal