CMake Nightly Date Stamp
find_library: Find shared libraries with numerical suffixes

Commit 342fc040 (Recognize shared library files with a numerical
suffix, 2013-04-11) taught cmComputeLinkInformation to handle
shared libraries with numerical suffixes. Before this commit,
find_library ignored such shared libraries. This is a problem
for finding libGL.so.1 on a raspberryPi. Apparently there
is no libGL.so without a numeric suffix, so the GL library can
not be found.
Add compiler target compile options.

For clang, this allows passing -target <triple> to the compiler, and
for qcc, -V<arch> using toolchain files containing something like

 set(triple arm-linux-gnueabihf)
 set(CMAKE_C_COMPILER "/usr/bin/clang")
 set(CMAKE_C_COMPILER_TARGET ${triple})
 set(CMAKE_CXX_COMPILER "/usr/bin/clang++")
 set(CMAKE_CXX_COMPILER_TARGET ${triple})

or

 set(arch gcc_ntoarmv7le)
 set(CMAKE_C_COMPILER /opt/qnx650/host/linux/x86/usr/bin/qcc)
 set(CMAKE_C_COMPILER_TARGET ${arch})
 set(CMAKE_CXX_COMPILER /opt/qnx650/host/linux/x86/usr/bin/QCC)
 set(CMAKE_CXX_COMPILER_TARGET ${arch})

Both clang and qcc are inherently cross compiler( driver)s.

When cross-compiling with clang, use the CMAKE_${lang}_COMPILER_TARGET
as the _CMAKE_TOOLCHAIN_PREFIX to find the appropriate binutils.

When cross-compiling with QNX qcc, use the CMAKE_${lang}_COMPILER_TARGET
to set the appropriate _CMAKE_TOOLCHAIN_PREFIX.
Allow toolchain files to specify an external toolchain.

Clang can compile code, but uses the gcc tools for other tasks such
as linking. The -gcc-toolchain option can be used for that, but
generalize so that other compilers can be treated the same.

If such a location is specified, use it as a hint for finding
the binutils executables.
Merge topic 'find-libs-numeric-suffix' into next

2e38093 find_library: Find shared libraries with numerical suffixes
Help: Format manual/*.1.rst options as definition lists

Convert the command-line option documentation formatting from bullet
lists to definition lists.
Merge topic 'doc-tool-options-as-definition-lists' into next

3442f2b Help: Format manual/*.1.rst options as definition lists
MSVC: Fix encoding of Visual Studio 10+ project files.

Use Windows-1252, which is the same encoding as older
Visual Studio project files.
Merge topic 'msvc-encoding' into next

58e3d49 MSVC: Fix encoding of Visual Studio 10+ project files.
GetPrerequisites:  Preserve search path order from caller.
Merge topic 'gp-ld_library_path' into next

e130b9e GetPrerequisites:  Preserve search path order from caller.
Merge topic 'ExternalData-allow-no-urls'

8eb20ee ExternalData: Allow local stores without any URL templates
Merge topic 'configure_file-drop-IMMEDIATE'

15610bb Drop use of configure_file IMMEDIATE option
Merge topic 'set_emptyvar_PARENT_SCOPE'

bf755c7 set: Add unit tests for set/unset PARENT_SCOPE
bc280f1 set: Fix handling of empty value with PARENT_SCOPE
20afbd5 set: Handle value-less PARENT_SCOPE explicitly
Merge topic 'msvc-encoding'

58e3d49 MSVC: Fix encoding of Visual Studio 10+ project files.
Merge topic 'openmp-cray'

ebf70b0 FindOpenMP: fix detecting compilers that do not need any special flag (#14567)
Merge topic 'gp-ld_library_path'

e130b9e GetPrerequisites:  Preserve search path order from caller.
Merge topic 'doc-tool-options-as-definition-lists'

3442f2b Help: Format manual/*.1.rst options as definition lists
Merge branch 'master' into next
Use --sysroot when cross compiling.

As CMAKE_ROOT_FIND_PATH can be a list, a new CMAKE_SYSROOT is
introduced, which is never a list.

The contents of this variable is passed to supporting compilers
as --sysroot. It is also accounted for when processing implicit
link directories reported by the compiler, and when generating
RPATH information. The CMAKE_SYSROOT is also prefixed to the
CMAKE_INSTALL_PREFIX as the final install location. A follow-up
commit will introduce a new variable for a staging prefix as an
alternative.

A toolchain file will generally contain the following lines:

 set(CMAKE_SYSROOT /path/to/sysroot)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

The find_file in Modules/CMakeDetermineCompilerId.cmake should not
look in the sysroot or the CMAKE_FIND_ROOT_PATH entries, so
add the parameter to control that in CMakeDetermineCompilerId.cmake.