Do not emit variables for enum declarations.

GitHub: Fixes #762.
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.
Merge pull request #774 from redstar/mingw

Fix mingw build script.
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 pull request #776 from redstar/deflib

Do not emit /DEFAULTLIB:<lib> on mingw
Merge of the ARM EH work by David.

See issue #489.
Merge pull request #777 from redstar/armeh

Merge of the ARM EH work by David.
Fix LLVM 3.6 compile error.

END_WITH_NULL is now named LLVM_END_WITH_NULL.
LLVM 3.6: Name and signature of FindProrammByName changed.
LLVM 3.6: Fix wrong logic for new FindProgramByName.
Merge pull request #763 from klickverbot/enum-codegen

Do not emit variables for enum declarations.
Implement longdouble as a wrapper around llvm::APFloat.

This commit introduces a new class ldc::longdouble which provides real_t
semantics based on the target. It uses llvm::APFloat as base implementation.

This fixes issue #259.
Implement Port::fequal().