Help: Remove out of date bounds on compile feature supported versions

The upper limits on what compiler CMake supports is always changing,
and the values inside cmake-compile-feature is always out of date.
So lets remove it.

Help/manual/cmake-compile-features.7.rst

@@ -331,12 +331,12 @@ and :prop_gbl:`compile features <CMAKE_CXX_KNOWN_FEATURES>` available from
 the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:
 
-* ``AppleClang``: Apple Clang for Xcode versions 4.4 though 9.2.
-* ``Clang``: Clang compiler versions 2.9 through 6.0.
-* ``GNU``: GNU compiler versions 4.4 through 8.0.
-* ``MSVC``: Microsoft Visual Studio versions 2010 through 2017.
-* ``SunPro``: Oracle SolarisStudio versions 12.4 through 12.6.
-* ``Intel``: Intel compiler versions 12.1 through 17.0.
+* ``AppleClang``: Apple Clang for Xcode versions 4.4+.
+* ``Clang``: Clang compiler versions 2.9+.
+* ``GNU``: GNU compiler versions 4.4+.
+* ``MSVC``: Microsoft Visual Studio versions 2010+.
+* ``SunPro``: Oracle SolarisStudio versions 12.4+.
+* ``Intel``: Intel compiler versions 12.1+.
 
 CMake is currently aware of the :prop_tgt:`C standards <C_STANDARD>`
 and :prop_gbl:`compile features <CMAKE_C_KNOWN_FEATURES>` available from
@@ -344,16 +344,16 @@ the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:
 
 * all compilers and versions listed above for C++.
-* ``GNU``: GNU compiler versions 3.4 through 8.0.
+* ``GNU``: GNU compiler versions 3.4+
 
 CMake is currently aware of the :prop_tgt:`C++ standards <CXX_STANDARD>` and
 their associated meta-features (e.g. ``cxx_std_11``) available from the
 following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:
 
-* ``Cray``: Cray Compiler Environment version 8.1 through 8.5.8.
-* ``PGI``: PGI version 12.10 through 17.5.
-* ``XL``: IBM XL version 10.1 through 13.1.5.
+* ``Cray``: Cray Compiler Environment version 8.1+.
+* ``PGI``: PGI version 12.10+.
+* ``XL``: IBM XL version 10.1+.
 
 CMake is currently aware of the :prop_tgt:`C standards <C_STANDARD>` and
 their associated meta-features (e.g. ``c_std_99``) available from the
@@ -367,4 +367,4 @@ CMake is currently aware of the :prop_tgt:`CUDA standards <CUDA_STANDARD>`
 from the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:
 
-* ``NVIDIA``: NVIDIA nvcc compiler 7.5 though 9.1.
+* ``NVIDIA``: NVIDIA nvcc compiler 7.5+.