Comment parsing: put more information into the generated XML documents

This commit adds infrastructure for conversion and testing it.

The conversion is still incomplete, pending discussion about which tags should
we use in the XML documents.  I copied the RelaxNG schema from Clang, and will
edit it accordingly.


Swift SVN r16451

Author: gribozavr

CMakeLists.txt

@@ -206,6 +206,12 @@ else()
    set(SWIFT_COMPILER "${PATH_TO_SWIFT_BUILD}/${CMAKE_CFG_INTDIR}/bin/swift")
 endif()
 
+# FIXME: unify with CLANG_HAVE_LIBXML, which is set in LLVM anyway.
+find_package(LibXml2)
+if(LIBXML2_FOUND)
+  set(SWIFT_HAVE_LIBXML 1)
+endif()
+
 # Xcode: use libc++ and c++11 using proper build settings.
 if ( XCODE )
   # Force usage of Clang.