[llvm] r212522 - [mips] Improve encapsulation of the .MIPS.abiflags implementation and limit scope of related enums

[Tim Northover]

Hi Daniel,

This mistmatch is causing warnings when built with Clang:

+struct MipsABIFlagsSection {
[...[
+class MipsABIFlagsSection;

>From what I understand (poorly) it might well fail on some MS ABI
platforms too, where structs and classes get different mangling.

Cheers.

Tim.