fix(api/nvim_win_call): share common win_execute logic

We have to be sure that the bugs fixed in the previous patches also apply to
nvim_win_call.

Checking v8.1.2124 and v8.2.4026 is especially important as these patches were
only applied to win_execute, but nvim_win_call is also affected by the same
bugs. A lot of win_execute's logic can be shared with nvim_win_call, so factor
it out into a common macro to reduce the possibility of this happening again.

src/nvim/window.h

@@ -4,6 +4,7 @@
 #include <stdbool.h>
 
 #include "nvim/buffer_defs.h"
+#include "nvim/mark.h"
 
 // Values for file_name_in_line()
 #define FNAME_MESS      1       // give error message
@@ -40,6 +41,30 @@ typedef struct {
   bool sw_visual_active;
 } switchwin_T;
 
+/// Execute a block of code in the context of window `wp` in tabpage `tp`.
+/// Ensures the status line is redrawn and cursor position is valid if it is moved.
+#define WIN_EXECUTE(wp, tp, block) \
+  do { \
+    win_T *const wp_ = (wp); \
+    const pos_T curpos_ = wp_->w_cursor; \
+    switchwin_T switchwin_; \
+    if (switch_win_noblock(&switchwin_, wp_, (tp), true) == OK) { \
+      check_cursor(); \
+      block; \
+    } \
+    restore_win_noblock(&switchwin_, true); \
+    /* Update the status line if the cursor moved. */ \
+    if (win_valid(wp_) && !equalpos(curpos_, wp_->w_cursor)) { \
+      wp_->w_redr_status = true; \
+    } \
+    /* In case the command moved the cursor or changed the Visual area, */ \
+    /* check it is valid. */ \
+    check_cursor(); \
+    if (VIsual_active) { \
+      check_pos(curbuf, &VIsual); \
+    } \
+  } while (false)
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "window.h.generated.h"
 #endif