[PATCH] x86_64: Fix section relocation for SECTIONREL32 with immediate offset

[Rafael Espíndola]

> The attached test case is a .ll file because llvm-mc does not support
> @SECTIONREL32.

Would that be too hard to add? It would be much better if we could
test this with assembly.

Assembling

    movq    values at SECREL32(%rax), %rcx
    movq    values at SECREL32+8(%rax), %rax

with gas and then running llvm-reoadobj -r I got

    0x3 IMAGE_REL_AMD64_SECREL values
    0xA IMAGE_REL_AMD64_SECREL values

Cheers,
Rafael