Fix wrong code offset for unwind code SET_FPREG.

The code offset for unwind code SET_FPREG is wrong because it is set
to constant 0. The fix is to do the same as for the other unwind
codes: emit a label and later the absolute difference between the
label and the begin of the prologue.
Also enables the failing test case MC/COFF/seh.s

Reviewed by Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185758 91177308-0d34-0410-b5e6-96231b3b80d8
Generate IMAGE_REL_AMD64_ADDR32NB relocations for SEH
 data structures.

The Win64 EH data structures must be of type IMAGE_REL_AMD64_ADDR32NB
instead of IMAGE_REL_AMD64_ADDR32. This is easiely achieved by adding
the VK_COFF_IMGREL32 modifier to the symbol reference.
Change also references to start and end of the SEH range of a function
as offsets to start of the function.

Reviewed by Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185759 91177308-0d34-0410-b5e6-96231b3b80d8
Fix alignment of unwind data.

For alignment purposes, the instruction array will always have an even
number of entries, with the final entry potentially unused (in which
case the array will be one longer than indicated by the count of unwind
codes field).

Reviewed by Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185760 91177308-0d34-0410-b5e6-96231b3b80d8
Emit personality function and Dwarf EH data for Win64 SEH.

Obviously the personality function should be emitted as language handler
instead of the hard coded _GCC_specific_handler. The language specific
data must be placed after the unwind information therefore it must not
be emitted into a separate section.

Reviewed by Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185761 91177308-0d34-0410-b5e6-96231b3b80d8