See issue #2762
Adds full_version to class Compiler. If set full_version will be printed
additionally.
Added support for CCompiler and CPPCompiler
Added support for gcc/g++, clang/clang++, icc.
CCache requires this flag when building with precompiled headers.
Without it, the preprocessor fails and CCache fallbacks to running the
real compiler.
Users still need to set 'sloppiness' to 'pch_defines,time_macros' in
their ccache.conf file for CCache to cache builds that use precompiled
headers. See the CCache manual for more info:
https://ccache.samba.org/manual.html#_precompiled_headers