Supports Sourcery CodeBench Mips toolchain directories tree.

Sourcery CodeBench and modern FSF Mips toolchains require a bit more
complicated algorithm to calculate headers, libraries and sysroot paths
than implemented by Clang driver now. The main problem is that all these
paths depend on a set of command line arguments additionally to a target
triple value. For example, let $TC is a toolchain installation directory.
If we compile big-endian 32-bit mips code, crtbegin.o is in the
$TC/lib/gcc/mips-linux-gnu/4.7.2 folder and the toolchain's linker requires
--sysroot=$TC/mips-linux-gnu/libc argument. If we compile little-endian
32-bit soft-float mips code, crtbegin.o is in the
$TC/lib/gcc/mips-linux-gnu/4.7.2/soft-float/el folder and the toolchain's
linker requires --sysroot=$TC/mips-linux-gnu/libc/soft-float/el argument.

1. Calculate MultiarchSuffix using all necessary command line options and
   use this MultiarchSuffix to detect crtbegin.o location in the
   GCCInstallationDetector::ScanLibDirForGCCTriple() routine.
2. If a user does not provide --sysroot argument to the driver explicitly,
   calculate new sysroot value based on command line options. Then use this
   calculated sysroot path:
   a. To populate a file search paths list in the Linux::Linux() constructor.
   b. To find Mips toolchain specific include headers directories
      in the Linux::AddClangSystemIncludeArgs() routine.
   c. To provide -–sysroot argument for a linker.

Note:
- The FSF's tree slightly differs (folder names) and is not supported
  yet.
- New addExternCSystemIncludeIfExits() routine is a temporary solution.
  I plan to move path existence check to the addExternCSystemInclude()
  routine by a separate commit.

The patch reviewed by Rafael Espindola.
http://llvm-reviews.chandlerc.com/D644

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179934 91177308-0d34-0410-b5e6-96231b3b80d8
Implement core issue 1608: class members can be found via operator lookup in a trailing return type in that class's body.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179941 91177308-0d34-0410-b5e6-96231b3b80d8
Binary literals are approved for C++14.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179942 91177308-0d34-0410-b5e6-96231b3b80d8
More approved C++14 features.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179943 91177308-0d34-0410-b5e6-96231b3b80d8
Generalized constexpr is approved for C++14.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179944 91177308-0d34-0410-b5e6-96231b3b80d8
No digit separators for C++14.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179945 91177308-0d34-0410-b5e6-96231b3b80d8
Clarifying memory allocation: approved for C++14. Move from N/A to no, since we currently relax 'operator new' calls which didn't come from new-expressions.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179946 91177308-0d34-0410-b5e6-96231b3b80d8
Variable templates and generic lambdas are approved for C++14.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179947 91177308-0d34-0410-b5e6-96231b3b80d8
VLAs in C++14!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179949 91177308-0d34-0410-b5e6-96231b3b80d8
Add note that some of these links are dead for now.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179950 91177308-0d34-0410-b5e6-96231b3b80d8
Switch C++11 open project to C++1y :)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179951 91177308-0d34-0410-b5e6-96231b3b80d8
Update some stuff on the open projects page to reflect things we've already done.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179953 91177308-0d34-0410-b5e6-96231b3b80d8
C++1y: Allow aggregates to have default initializers.

Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.

There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179958 91177308-0d34-0410-b5e6-96231b3b80d8
Add another test I forgot to svn add.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179959 91177308-0d34-0410-b5e6-96231b3b80d8
Disable VLA diagnostic in C++1y mode, and add some tests.

Still to do here:
  - we have a collection of syntactic accepts-invalids to diagnose
  - support non-PODs in VLAs, including dynamic initialization /
    destruction
  - runtime checks (and throw std::bad_array_length) for bad bound
  - support VLA capture by reference in lambdas
  - properly support VLAs in range-based for (don't recompute bound)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179962 91177308-0d34-0410-b5e6-96231b3b80d8
The 'constexpr implies const' rule for non-static member functions is gone in
C++1y, so stop adding the 'const' there. Provide a compatibility warning for
code relying on this in C++11, with a fix-it hint. Update our lazily-written
tests to add the const, except for those ones which were testing our
implementation of this rule.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179969 91177308-0d34-0410-b5e6-96231b3b80d8