IR: Add COMDATs to the IR

Description

IR: Add COMDATs to the IR

This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

Details

Committed
majnemerJun 27 2014, 11:19 AM
Differential Revision
D4178: Alternative way of representing comdats
Parents
rL211919: cmake: Don't do anything for LLVM_ENABLE_ASSERTIONS=OFF
Branches
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