Do not emit variables for enum declarations.

GitHub: Fixes #762.
Fix compile error with LLVM 3.6.

The llvm::Linker class now uses diagnostic messages.
Revert "Fix compile error with LLVM 3.6."

This reverts commit cc829485cc70dd74699f315534ae1634a75e78a5.
Merge of missing changes for 2.066.1.

Merge up to 0588458.
Allow overriding of header files.

This is the same behavior as DMD.
Fix compile error with LLVM 3.6.

The llvm::Linker class now uses diagnostic messages.
Implement missing -boundscheck switch in ldmd.

This was reported in the newsgroup by Daniel N.
Changes for Win64 and PPC32/64

- Added math function using MSVC runtime
- Added PPC inline assembler for getStackTop()
Fix yet another LLVM 3.6 compile error with the llvm::Linker class.

The value llvm::Linker::DestroySource was removed.
Linux/PPC64: Statically define ELFv1 for Big Endian and ELFv2 for Little Endian Systems.

This is in preparation for the missing `--with-abi=` command line switch.
ELFv1 and ELFv2 are reserved version identifiers starting with DMD 2.067.
PPC: Improvements to core.thread
Better dumping of predefined version identifiers.

Also count spaces in order to limit line length to 80.
Fix compiler error introduced with 66610543995246cc5d552c83726aed0fbd2c12f2.
Implement core.checkedint in terms of LLVM intrinsics.
Fix all failing std.math unit tests
Fix mingw build script.

LLVM 3.5 requires use of C++11. The gcc compiler requires a flag to use C++11.
The easiest way to pass this flags is to uses the flags returend by llvm-config.
Using llvm-config with mingw requires some path fiddeling because of the mixed
Windows and Unix conventions.
CMake: Fix -Werror stripping.

The old code broke on Fedora, where "-Werror=format-security"
is part of the llvm-config --cxxflags.

GitHub: Fixes #773.
Fix mingw version of std.stdio.

With this commit it is again possible to build ldc on mingw32 platform.
Do not emit /DEFAULTLIB:<lib> on mingw

Yet another error caused by the new triple handling in LLVM 3.5.
Merge of the ARM EH work by David.

See issue #489.