Fixed a bug in DtoInlineIR

Before this fix, debug info was removed from the module while
parsing inline ir.
Added a check for vector size to gen_gccbuiltins.cpp.

Previously, gen_gccbuiltins was emitting intrinsics
that used vector types larger than 256 bits and those
are not defined in core.simd.
Merge pull request #569 from jerro/bugfix

Bugfix
Fix build with LLVM 3.5
Fix include for LLVM 3.5
Change compiler options for MSVC.

This fixes issue #458.
Fix the LLVM 3.5 build.

Some classes were moved into IR folder.
Fix more files for LLVM 3.5.
DLL linkage is decoupled from linkage in LLVM 3.5.
Fix new signature of verifyModule() in LLVM 3.5.
Add sanitizer attributes.

If the sanitizer is enabled (e.g. -sanitize=address) then the corresponding
attribute (e.g. llvm::Attribute::SanitizerAddress) must be set.
Emit ldc version as llvm.ident metadata.
Fixes #544

Including `<iostream>` allows LDC to compile correctly on some Macs running OS X Mavericks.
Merge pull request #583 from itaiferber/master

Fixes #544