Add language to test
Merge topic 'GNU-4.7-features' into next

0b5bed07 Add language to test
Features: Record for GNU 4.7.

Update the CompileFeatures test to verify that unsupported features
do not work.
Merge topic 'GNU-4.7-features' into next

8d2cb84c Features: Record for GNU 4.7.
Generalize language-specific variables.
Merge topic 'compiler-id-refactor' into next

cefa066b Generalize language-specific variables.
Project: Clarify comment about platform-native compilers.
Project: Generate the CXX compiler Id test from multiple files.

This will allow sharing of the logic of the order to test compilers in
and the preprocessor macros used to do that and to determine the
version components.
Project: Split the compiler id detection into a separate function.

This can be extended with parameters to control the output and re-used
in other contexts.
CompilerId: Allow specifying the compiler-specific components to generate.
CompilerId: Add option to generate compiler-id-specific defines.
CompilerId: Guard the platform-default compiler code with a parameter.
CompilerId: Allow specifying a prefix for preprocessor defines.
Merge topic 'compiler-id-refactor' into next

cbada666 CompilerId: Allow specifying a prefix for preprocessor defines.
aa3bef37 CompilerId: Guard the platform-default compiler code with a parameter.
cd4905b0 CompilerId: Add option to generate compiler-id-specific defines.
2c1b2de3 CompilerId: Allow specifying the compiler-specific components to generate.
69595da8 Project: Split the compiler id detection into a separate function.
47a697fd Project: Generate the CXX compiler Id test from multiple files.
c7ddd409 Project: Clarify comment about platform-native compilers.