vim-patch:8.2.0296: mixing up "long long" and __int64 may cause problems

Problem:    Mixing up "long long" and __int64 may cause problems. (John
            Marriott)
Solution:   Pass varnumber_T to vim_snprintf().  Add v:numbersize.
f9706e9df0

src/nvim/eval.c

@@ -213,6 +213,7 @@ static struct vimvar {
   VV(VV_FALSE,          "false",            VAR_BOOL, VV_RO),
   VV(VV_TRUE,           "true",             VAR_BOOL, VV_RO),
   VV(VV_NULL,           "null",             VAR_SPECIAL, VV_RO),
+  VV(VV_NUMBERSIZE,     "numbersize",       VAR_NUMBER, VV_RO),
   VV(VV_VIM_DID_ENTER,  "vim_did_enter",    VAR_NUMBER, VV_RO),
   VV(VV_TESTING,        "testing",          VAR_NUMBER, 0),
   VV(VV_TYPE_NUMBER,    "t_number",         VAR_NUMBER, VV_RO),
@@ -394,6 +395,7 @@ void eval_init(void)
   set_vim_var_bool(VV_FALSE, kBoolVarFalse);
   set_vim_var_bool(VV_TRUE, kBoolVarTrue);
   set_vim_var_special(VV_NULL, kSpecialVarNull);
+  set_vim_var_nr(VV_NUMBERSIZE, sizeof(varnumber_T) * 8);
   set_vim_var_special(VV_EXITING, kSpecialVarNull);
 
   set_vim_var_nr(VV_ECHOSPACE,    sc_col - 1);

src/nvim/eval.h

@@ -142,6 +142,7 @@ typedef enum {
     VV_FALSE,
     VV_TRUE,
     VV_NULL,
+    VV_NUMBERSIZE,
     VV_VIM_DID_ENTER,
     VV_TESTING,
     VV_TYPE_NUMBER,

src/nvim/testdir/test_eval_stuff.vim

@@ -120,6 +120,12 @@ func Test_skip_after_throw()
   endtry
 endfunc
 
+func Test_numbersize()
+  " This will fail on systems without 64 bit int support or when not configured
+  " correctly.
+  call assert_equal(64, v:numbersize)
+endfunc
+
 func Test_curly_assignment()
   let s:svar = 'svar'
   let g:gvar = 'gvar'