add cross-platform test for cmake_module_path

This test tolerates CMake >= 3.7, and checks that

    dependency(..., cmake_module_path=...) works on any OS with CMake.

test cases/cmake/10 cmake_module_path/cmake/FindSomethingLikePython.cmake

@@ -0,0 +1,24 @@
+cmake_policy(VERSION 3.7)
+
+if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12)
+  find_package(Python COMPONENTS Interpreter)
+else()
+  find_package(PythonInterp)
+endif()
+
+if(Python_FOUND OR PYTHONINTERP_FOUND)
+  set(SomethingLikePython_FOUND      ON)
+  set(SomethingLikePython_EXECUTABLE ${Python_EXECUTABLE})
+
+  if(NOT DEFINED Python_VERSION)
+    set(Python_VERSION ${Python_VERSION_STRING})
+  endif()
+  if(NOT TARGET Python::Interpreter)
+    add_executable(Python::Interpreter IMPORTED)
+    set_target_properties(Python::Interpreter PROPERTIES
+                          IMPORTED_LOCATION ${Python_EXECUTABLE}
+                          VERSION ${Python_VERSION})
+  endif()
+else()
+  set(SomethingLikePython_FOUND OFF)
+endif()

test cases/cmake/10 cmake_module_path/meson.build

@@ -0,0 +1,17 @@
+# We use Python3 as it's the only thing guaranteed to be available on any platform Meson can run on (unlike Zlib in linuxlike/13 cmake dependency).
+
+project('user CMake find_package module using cmake_module_path',
+  meson_version: '>= 0.50.0')
+
+if not find_program('cmake', required: false).found()
+  error('MESON_SKIP_TEST cmake binary not available.')
+endif
+
+# NOTE: can't request Python3 via dependency('Python3', method: 'cmake')
+#  Meson intercepts and wants "method: auto"
+
+# Try to find a dependency with a custom CMake module
+
+dependency('SomethingLikePython', required : true, method : 'cmake', cmake_module_path : 'cmake', modules: 'Python::Interpreter')
+
+dependency('SomethingLikePython', method : 'cmake', cmake_module_path : ['doesNotExist', 'cmake'], modules: 'Python::Interpreter')