Delete structs.h by spliting it and moving code to other headers

Here's the list of squashed commits (for more info, see PR #378).

 - Define guicolor_T as a typedef in syntax.h
 - Move a big chunk of code from structs.h to buffer_defs.h
 - Move aco_save_T from structs.h to fileio.h
 - Move option_table_T from structs.h to hardcopy.h

	Aditionally:

	 - Move the printer_opts global to hardcopy.c
	 - Delete structs.h. Include buffer_defs.h where structs.h was included
	   before.
	 - Add header guards to option_defs.h

 - Put mark types and constants in new mark_defs.h
 - Move undo structs to undo_defs.h
 - Move memfile structs to new memfile_defs.h
 - Move expand_T and cmdmod_T to ex_cmds_defs.h
 - Move memline_T to memline_defs.h
 - Move many defs and types to ex_eval.h
 - Move syntax related types to syntax_defs.h
 - Move struct memfile to memfile_defs.h
 - struct buffblock and struct buffheader moved back to buffer_defs.h
 - Move some datatypes to hashtab.h and eval_defs.h
 - Move the buffer_defs.h include and TODOs for remaining unrelated types in buffer_defs.h

1 files changed, 120 insertions, 0 deletions

diff --git a/src/eval_defs.h b/src/eval_defs.h
new file mode 100644
index 0000000000..c925514597
--- /dev/null
+++ b/src/eval_defs.h
@@ -0,0 +1,120 @@
+#ifndef NEOVIM_EVAL_DEFS_H
+#define NEOVIM_EVAL_DEFS_H
+
+#include "hashtab.h"
+
+#if SIZEOF_INT <= 3             /* use long if int is smaller than 32 bits */
+typedef long varnumber_T;
+#else
+typedef int varnumber_T;
+#endif
+typedef double float_T;
+
+typedef struct listvar_S list_T;
+typedef struct dictvar_S dict_T;
+
+/*
+ * Structure to hold an internal variable without a name.
+ */
+typedef struct {
+  char v_type;              /* see below: VAR_NUMBER, VAR_STRING, etc. */
+  char v_lock;              /* see below: VAR_LOCKED, VAR_FIXED */
+  union {
+    varnumber_T v_number;               /* number value */
+    float_T v_float;                    /* floating number value */
+    char_u          *v_string;          /* string value (can be NULL!) */
+    list_T          *v_list;            /* list value (can be NULL!) */
+    dict_T          *v_dict;            /* dict value (can be NULL!) */
+  }           vval;
+} typval_T;
+
+/* Values for "v_type". */
+#define VAR_UNKNOWN 0
+#define VAR_NUMBER  1   /* "v_number" is used */
+#define VAR_STRING  2   /* "v_string" is used */
+#define VAR_FUNC    3   /* "v_string" is function name */
+#define VAR_LIST    4   /* "v_list" is used */
+#define VAR_DICT    5   /* "v_dict" is used */
+#define VAR_FLOAT   6   /* "v_float" is used */
+
+/* Values for "dv_scope". */
+#define VAR_SCOPE     1 /* a:, v:, s:, etc. scope dictionaries */
+#define VAR_DEF_SCOPE 2 /* l:, g: scope dictionaries: here funcrefs are not
+                           allowed to mask existing functions */
+
+/* Values for "v_lock". */
+#define VAR_LOCKED  1   /* locked with lock(), can use unlock() */
+#define VAR_FIXED   2   /* locked forever */
+
+/*
+ * Structure to hold an item of a list: an internal variable without a name.
+ */
+typedef struct listitem_S listitem_T;
+
+struct listitem_S {
+  listitem_T  *li_next;         /* next item in list */
+  listitem_T  *li_prev;         /* previous item in list */
+  typval_T li_tv;               /* type and value of the variable */
+};
+
+/*
+ * Struct used by those that are using an item in a list.
+ */
+typedef struct listwatch_S listwatch_T;
+
+struct listwatch_S {
+  listitem_T          *lw_item;         /* item being watched */
+  listwatch_T         *lw_next;         /* next watcher */
+};
+
+/*
+ * Structure to hold info about a list.
+ */
+struct listvar_S {
+  listitem_T  *lv_first;        /* first item, NULL if none */
+  listitem_T  *lv_last;         /* last item, NULL if none */
+  int lv_refcount;              /* reference count */
+  int lv_len;                   /* number of items */
+  listwatch_T *lv_watch;        /* first watcher, NULL if none */
+  int lv_idx;                   /* cached index of an item */
+  listitem_T  *lv_idx_item;     /* when not NULL item at index "lv_idx" */
+  int lv_copyID;                /* ID used by deepcopy() */
+  list_T      *lv_copylist;     /* copied list used by deepcopy() */
+  char lv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
+  list_T      *lv_used_next;    /* next list in used lists list */
+  list_T      *lv_used_prev;    /* previous list in used lists list */
+};
+
+/*
+ * Structure to hold an item of a Dictionary.
+ * Also used for a variable.
+ * The key is copied into "di_key" to avoid an extra alloc/free for it.
+ */
+struct dictitem_S {
+  typval_T di_tv;               /* type and value of the variable */
+  char_u di_flags;              /* flags (only used for variable) */
+  char_u di_key[1];             /* key (actually longer!) */
+};
+
+typedef struct dictitem_S dictitem_T;
+
+#define DI_FLAGS_RO     1 /* "di_flags" value: read-only variable */
+#define DI_FLAGS_RO_SBX 2 /* "di_flags" value: read-only in the sandbox */
+#define DI_FLAGS_FIX    4 /* "di_flags" value: fixed variable, not allocated */
+#define DI_FLAGS_LOCK   8 /* "di_flags" value: locked variable */
+
+/*
+ * Structure to hold info about a Dictionary.
+ */
+struct dictvar_S {
+  char dv_lock;                 /* zero, VAR_LOCKED, VAR_FIXED */
+  char dv_scope;                /* zero, VAR_SCOPE, VAR_DEF_SCOPE */
+  int dv_refcount;              /* reference count */
+  int dv_copyID;                /* ID used by deepcopy() */
+  hashtab_T dv_hashtab;         /* hashtab that refers to the items */
+  dict_T      *dv_copydict;     /* copied dict used by deepcopy() */
+  dict_T      *dv_used_next;    /* next dict in used dicts list */
+  dict_T      *dv_used_prev;    /* previous dict in used dicts list */
+};
+
+#endif // NEOVIM_EVAL_DEFS_H