Merge topic 'dev/custom-ninja-deptypes'

9523d2a5 ninja: Add support for custom depfile formats

Help/release/dev/custom-ninja-deptypes.rst

+custom-ninja-deptypes
+---------------------
+
+* Add a `CMAKE_NINJA_DEPTYPE_<LANG>` variable so that compilers may set the
+  deptype for use in Ninja other than those CMake itself knows about.

Source/cmNinjaTargetGenerator.cxx

@@ -418,6 +418,11 @@ cmNinjaTargetGenerator
   else
     {
     deptype = "gcc";
+    const char* langdeptype = mf->GetDefinition("CMAKE_NINJA_DEPTYPE_" + lang);
+    if (langdeptype)
+      {
+      deptype = langdeptype;
+      }
     depfile = "$DEP_FILE";
     const std::string flagsName = "CMAKE_DEPFILE_FLAGS_" + lang;
     std::string depfileFlags = mf->GetSafeDefinition(flagsName);