Tests for DR370-380.

Also promote a couple of Warnings on ill-formed code found by this testing to
ExtWarns.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203021 91177308-0d34-0410-b5e6-96231b3b80d8
DR status page: add link targets for individual DRs, and link duplicates.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203022 91177308-0d34-0410-b5e6-96231b3b80d8
Fix recursion bug in logic to validate 'objc_protocol_requires_explicit_implementation' conformance.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203024 91177308-0d34-0410-b5e6-96231b3b80d8
PR19010: Make sure we initialize (empty) indirect base class subobjects when
evaluating trivial default initialization of a literal class type.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203025 91177308-0d34-0410-b5e6-96231b3b80d8
[-Wunreachable-code] include some enum constants in "configuration value" heuristic

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203026 91177308-0d34-0410-b5e6-96231b3b80d8
[-Wunreachabe-code] add test for double 'break'.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203027 91177308-0d34-0410-b5e6-96231b3b80d8
Objective-C. Suppress the warning for auto synthesis of property not
synthesizing protocol properties if class's super class
implements them. // rdar://16089191


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203028 91177308-0d34-0410-b5e6-96231b3b80d8
[-Wunreachable-code] generalize pruning out warning on trivial returns.

Previously we only pruned dead returns preceded by a call to a
'noreturn' function.  After looking at the results of the LLVM codebase,
there are many others that should be pruned as well.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203029 91177308-0d34-0410-b5e6-96231b3b80d8