[vcpkg] Add vcpkg_check_features (#6958)

* [vcpkg] Add vcpkg_check_feature, vcpkg_check_features

* [vcpkg] Remove vcpkg_check_feature

* [oniguruma,xtensor] Use vcpkg_check_features

2 files changed, 42 insertions, 0 deletions

diff --git a/docs/maintainers/portfile-functions.md b/docs/maintainers/portfile-functions.md
index c4b810dc0..b98d89192 100644
--- a/docs/maintainers/portfile-functions.md
+++ b/docs/maintainers/portfile-functions.md
@@ -6,6 +6,7 @@
 - [vcpkg\_apply\_patches](vcpkg_apply_patches.md)

 - [vcpkg\_build\_cmake](vcpkg_build_cmake.md)

 - [vcpkg\_build\_msbuild](vcpkg_build_msbuild.md)

+- [vcpkg\_check\_features](vcpkg_check_features.md)

 - [vcpkg\_check\_linkage](vcpkg_check_linkage.md)

 - [vcpkg\_clean\_msbuild](vcpkg_clean_msbuild.md)

 - [vcpkg\_configure\_cmake](vcpkg_configure_cmake.md)

diff --git a/docs/maintainers/vcpkg_check_features.md b/docs/maintainers/vcpkg_check_features.md
new file mode 100644
index 000000000..ca2debf85
--- /dev/null
+++ b/docs/maintainers/vcpkg_check_features.md
@@ -0,0 +1,41 @@
+# vcpkg_check_features
+
+Check if one or more features are part of the package installation. 
+
+## Usage
+```cmake
+vcpkg_check_features(
+    <feature1> <output_variable1>
+    [<feature2> <output_variable2>]
+    ...
+)
+```
+
+`vcpkg_check_features` accepts a list of (feature, output_variable) pairs.
+The syntax is similar to the `PROPERTIES` argument of `set_target_properties`.
+
+`vcpkg_check_features` will create a variable `FEATURE_OPTIONS` in the
+parent scope, which you can pass as a part of `OPTIONS` argument when
+calling functions like `vcpkg_config_cmake`:
+```cmake
+vcpkg_config_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    PREFER_NINJA
+    OPTIONS
+        -DBUILD_TESTING=ON
+        ${FEATURE_OPTIONS}
+)
+```
+
+## Notes
+`vcpkg_check_features` is supposed to be called only once. Otherwise, the
+`FEATURE_OPTIONS` variable set by a previous call will be overwritten.
+
+## Examples
+
+* [czmq](https://github.com/microsoft/vcpkg/blob/master/ports/czmq/portfile.cmake)
+* [oniguruma](https://github.com/microsoft/vcpkg/blob/master/ports/oniguruma/portfile.cmake)
+* [xtensor](https://github.com/microsoft/vcpkg/blob/master/ports/xtensor/portfile.cmake)
+
+## Source
+[scripts/cmake/vcpkg_check_features.cmake](https://github.com/Microsoft/vcpkg/blob/master/scripts/cmake/vcpkg_check_features.cmake)