[lldb][NFC] Delete static versions of ClangASTContext::CreateFunctionType

We can always call the member function version of this function.
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
index ec1f347..6634824 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
@@ -1955,8 +1955,8 @@
         m_clang_ast_context->GetBasicType(eBasicTypeVoid);
     CompilerType void_ptr_clang_type = void_clang_type.GetPointerType();
 
-    CompilerType method_type = ClangASTContext::CreateFunctionType(
-        m_ast_context, void_clang_type, &void_ptr_clang_type, 1, false, 0);
+    CompilerType method_type = m_clang_ast_context->CreateFunctionType(
+        void_clang_type, &void_ptr_clang_type, 1, false, 0);
 
     const bool is_virtual = false;
     const bool is_static = false;