With CLANG_ENABLE_STATIC_ANALYZER=0, link clang properly and skip clang-check.

Previously, the CMake build still tried to link clang against the static
analyzer libraries, even if CLANG_ENABLE_STATIC_ANALYZER was off.
Furthermore, clang-check depends on the analyzer, so it should be disabled
(in both CMake and configure builds).

In theory, clang-check could be made to conditionally include analyzer
support (like clang itself), but for now this at least gets a CMake ALL_BUILD
working.

Patch by Stephen Kelly, modified by me.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@185548 91177308-0d34-0410-b5e6-96231b3b80d8
[scan-build] Log compiler invocation to stderr, not stdout.

This is important for preprocessing steps, which may output to stdout.

Also, change ENV accesses using barewords to use string keys instead.

PR16414

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@185555 91177308-0d34-0410-b5e6-96231b3b80d8