[mathtext] mv to builtin subdir for consistency (#22462)

* [mathtext] mv to builtins subdir for consistency with others

* [mathtext] update paths to builtin

* [mathtext] add license from original repo

* [mathtext] rename source file extension for easier diffing with upstream fork

Author: ferdymercury

CMakeLists.txt

@@ -403,6 +403,7 @@ add_subdirectory (hist)
 add_subdirectory (tree)
 add_subdirectory (io)
 add_subdirectory (net)
+add_subdirectory (builtins/mathtext) # hard coded builtin for graf2d
 add_subdirectory (graf2d)
 add_subdirectory (graf3d)
 if(NOT minimal)

graf2d/mathtext/CMakeLists.txt builtins/mathtext/CMakeLists.txtgraf2d/mathtext/CMakeLists.txt renamed to builtins/mathtext/CMakeLists.txt

@@ -5,22 +5,22 @@
 # For the list of contributors see $ROOTSYS/README/CREDITS.
 
 ROOT_LINKER_LIBRARY(mathtext
-  fontembed.cxx
-  fontembedps.cxx
-  mathrender.cxx
-  mathrenderstyle.cxx
-  mathrendertoken.cxx
-  mathtext.cxx
-  mathtextencode.cxx
-  mathtextparse.cxx
-  mathtextview.cxx
+  fontembed.cc
+  fontembedps.cc
+  mathrender.cc
+  mathrenderstyle.cc
+  mathrendertoken.cc
+  mathtext.cc
+  mathtextencode.cc
+  mathtextparse.cc
+  mathtextview.cc
   TYPE
     STATIC
   NOINSTALL
 )
 
 check_cxx_compiler_flag(-Wbidi-chars=none GCC_HAS_BIDI_CHARS_FLAG)
 if(GCC_HAS_BIDI_CHARS_FLAG)
-    set_source_files_properties(src/fontembed.cxx COMPILE_FLAGS "-Wbidi-chars=none")
+    set_source_files_properties(src/fontembed.cc COMPILE_FLAGS "-Wbidi-chars=none")
 endif()
 set_property(TARGET mathtext PROPERTY POSITION_INDEPENDENT_CODE ON)