- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Pull in r170135 from upstream clang trunk:

Dont use/link ARCMT, StaticAnalyzer and Rewriter to clang when the user
specifies not to. Dont build ASTMatchers with Rewriter disabled and
StaticAnalyzer when it's disabled.

Without all those three, the clang binary shrinks (x86_64) from ~36MB
to ~32MB (unstripped).

To disable these clang components, and get a smaller clang binary built
and installed, set WITHOUT_CLANG_FULL in src.conf(5). During the
initial stages of buildworld, those extra components are already
disabled automatically, to save some build time.

MFC after: 1 week

Upgrade our copy of llvm/clang to trunk r162107. With thanks to
Benjamin Kramer and Joerg Sonnenberger for their input and fixes.

Upgrade our Clang in base to r114020, from upstream's release_28 branch.

Approved-by: rpaulo (mentor)