refactor: move some structs out of buffer_defs.h (#24878)

src/nvim/mapping_defs.h

@@ -0,0 +1,29 @@
+#ifndef NVIM_MAPPING_DEFS_H
+#define NVIM_MAPPING_DEFS_H
+
+#include <stdbool.h>
+
+#include "nvim/eval/typval_defs.h"
+#include "nvim/types.h"
+
+/// Structure used for mappings and abbreviations.
+typedef struct mapblock mapblock_T;
+struct mapblock {
+  mapblock_T *m_next;       ///< next mapblock in list
+  char *m_keys;             ///< mapped from, lhs
+  char *m_str;              ///< mapped to, rhs
+  char *m_orig_str;         ///< rhs as entered by the user
+  LuaRef m_luaref;          ///< lua function reference as rhs
+  int m_keylen;             ///< strlen(m_keys)
+  int m_mode;               ///< valid mode
+  int m_simplified;         ///< m_keys was simplified
+  int m_noremap;            ///< if non-zero no re-mapping for m_str
+  char m_silent;            ///< <silent> used, don't echo commands
+  char m_nowait;            ///< <nowait> used
+  char m_expr;              ///< <expr> used, m_str is an expression
+  sctx_T m_script_ctx;      ///< SCTX where map was defined
+  char *m_desc;             ///< description of mapping
+  bool m_replace_keycodes;  ///< replace keycodes in result of expression
+};
+
+#endif  // NVIM_MAPPING_DEFS_H