Remove libcxx/include/cxxabi.h header as it does not belong to libcxx

ref:b9a880c5e3be99eec95cca2118f454e7c78a1de6

build/sysincl/stl-to-libcxx.yml

@@ -30,8 +30,7 @@
 
 - includes:
   - cxxabi.h:
-    - contrib/libs/cxxsupp/libcxx/include/cxxabi.h
-    - contrib/libs/cxxsupp/libcxxrt/cxxabi.h
+    - contrib/libs/cxxsupp/libcxxrt/include/cxxabi.h
   - omp.h:
     - contrib/libs/cxxsupp/openmp/omp.h
   - unwind.h:

contrib/libs/cxxsupp/libcxx/CMakeLists.txt

@@ -18,11 +18,12 @@ target_compile_options(libs-cxxsupp-libcxx PRIVATE
 )
 target_include_directories(libs-cxxsupp-libcxx PUBLIC
   ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxx/include
+  ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxxrt/include
 )
 target_include_directories(libs-cxxsupp-libcxx PRIVATE
   ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxx/include
   ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxx/src
-  ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxxrt
+  ${CMAKE_SOURCE_DIR}/contrib/libs/cxxsupp/libcxxrt/include
 )
 target_link_libraries(libs-cxxsupp-libcxx PUBLIC
   libs-cxxsupp-libcxxabi-parts

contrib/libs/cxxsupp/libcxx/include/cxxabi.h

@@ -1,9 +0,0 @@
-#pragma once
-
-#if defined(__IOS__) || defined(__ANDROID__)
-#include_next <cxxabi.h>
-#elif defined(_WIN32)
-// pass
-#else
-#include <contrib/libs/cxxsupp/libcxxrt/cxxabi.h>
-#endif

contrib/libs/cxxsupp/libcxxrt/include/cxxabi.h

@@ -0,0 +1 @@
+#include "../cxxabi.h" /* inclink generated by yamaker */