FindBoost: Avoid if() quoted auto-dereference

When testing CMAKE_CXX_COMPILER[_ID] values with if(MATCHES) or
if(STREQUAL), do not explicitly dereference or quote the variable.
We want if() to auto-dereference the variable and not its value.
Merge topic 'FindBoost-CMP0054' into next

c9300464 FindBoost: Avoid if() quoted auto-dereference
Merge topic 'FindThreads-macro'

94a061d3 FindThreads: use a macro for the repetitive thread library checks
Merge topic 'ninja-console-pool'

9f32a241 Ninja: Use 'console' pool for CMake re-run if possible (#14915)
Merge topic 'wix-fix-root-dir-prop'

fb009f00 CPackWiX: Work around RelativePath() returning an empty string for the root
Merge topic 'fix-cobertura-parsing'

1c838add cmParseCoberturaCoverage: Initialize CurFileName to empty string
Merge branch 'master' into next