refactor/single-include (#6687)

src/nvim/CMakeLists.txt

@@ -429,10 +429,6 @@ function(get_test_target prefix sfile relative_path_var target_var)
 endfunction()
 
 set(NO_SINGLE_CHECK_HEADERS
-  misc2.h
-  msgpack_rpc/server.h
-  os/shell.h
-  os_unix.h
   os/win_defs.h
   regexp_defs.h
   syntax_defs.h

src/nvim/msgpack_rpc/server.h

@@ -1,6 +1,8 @@
 #ifndef NVIM_MSGPACK_RPC_SERVER_H
 #define NVIM_MSGPACK_RPC_SERVER_H
 
+#include <stdio.h>
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "msgpack_rpc/server.h.generated.h"
 #endif

src/nvim/os/shell.h

@@ -1,6 +1,8 @@
 #ifndef NVIM_OS_SHELL_H
 #define NVIM_OS_SHELL_H
 
+#include <stdio.h>
+
 #include "nvim/types.h"
 
 // Flags for os_call_shell() second argument