Extract file_search.c from misc2.c

Continue to split misc2.c in many other files (see #209).

The only changed I made to the moved code was adding
`vim_free(ff_expand_buffer)` to `free_finfile()`. This is was needed
because `ff_expand_buffer` was moved from `misc2.c` to `file_search.c`.

src/eval.c

@@ -33,6 +33,7 @@
 #include "message.h"
 #include "misc1.h"
 #include "misc2.h"
+#include "file_search.h"
 #include "garray.h"
 #include "move.h"
 #include "normal.h"

src/ex_docmd.c

@@ -37,6 +37,7 @@
 #include "message.h"
 #include "misc1.h"
 #include "misc2.h"
+#include "file_search.h"
 #include "garray.h"
 #include "move.h"
 #include "normal.h"

src/file_search.h

@@ -0,0 +1,23 @@
+#ifndef NEOVIM_FIND_FILE_H
+#define NEOVIM_FIND_FILE_H
+
+void *vim_findfile_init __ARGS((char_u *path, char_u *filename, char_u *
+                                stopdirs, int level, int free_visited,
+                                int find_what, void *search_ctx_arg,
+                                int tagfile,
+                                char_u *rel_fname));
+char_u *vim_findfile_stopdir __ARGS((char_u *buf));
+void vim_findfile_cleanup __ARGS((void *ctx));
+char_u *vim_findfile __ARGS((void *search_ctx_arg));
+void vim_findfile_free_visited __ARGS((void *search_ctx_arg));
+char_u *find_file_in_path __ARGS((char_u *ptr, int len, int options, int first,
+                                  char_u *rel_fname));
+void free_findfile __ARGS((void));
+char_u *find_directory_in_path __ARGS((char_u *ptr, int len, int options,
+                                       char_u *rel_fname));
+char_u *find_file_in_path_option __ARGS((char_u *ptr, int len, int options,
+                                         int first, char_u *path_option,
+                                         int find_what, char_u *rel_fname,
+                                         char_u *suffixes));
+
+#endif /* NEOVIM_FIND_FILE_H */

src/misc2.h

@@ -91,23 +91,6 @@ void crypt_decode __ARGS((char_u *ptr, long len));
 void crypt_init_keys __ARGS((char_u *passwd));
 void free_crypt_key __ARGS((char_u *key));
 char_u *get_crypt_key __ARGS((int store, int twice));
-void *vim_findfile_init __ARGS((char_u *path, char_u *filename, char_u *
-                                stopdirs, int level, int free_visited,
-                                int find_what, void *search_ctx_arg,
-                                int tagfile,
-                                char_u *rel_fname));
-char_u *vim_findfile_stopdir __ARGS((char_u *buf));
-void vim_findfile_cleanup __ARGS((void *ctx));
-char_u *vim_findfile __ARGS((void *search_ctx_arg));
-void vim_findfile_free_visited __ARGS((void *search_ctx_arg));
-char_u *find_file_in_path __ARGS((char_u *ptr, int len, int options, int first,
-                                  char_u *rel_fname));
-char_u *find_directory_in_path __ARGS((char_u *ptr, int len, int options,
-                                       char_u *rel_fname));
-char_u *find_file_in_path_option __ARGS((char_u *ptr, int len, int options,
-                                         int first, char_u *path_option,
-                                         int find_what, char_u *rel_fname,
-                                         char_u *suffixes));
 int vim_chdir __ARGS((char_u *new_dir));
 int get_user_name __ARGS((char_u *buf, int len));
 void sort_strings __ARGS((char_u **files, int count));

src/tag.c

@@ -29,6 +29,7 @@
 #include "message.h"
 #include "misc1.h"
 #include "misc2.h"
+#include "file_search.h"
 #include "garray.h"
 #include "move.h"
 #include "option.h"

src/window.c

@@ -29,6 +29,7 @@
 #include "message.h"
 #include "misc1.h"
 #include "misc2.h"
+#include "file_search.h"
 #include "garray.h"
 #include "move.h"
 #include "normal.h"