parser: improve anon fn pos (#8210)

vlib/v/checker/tests/array_filter_anon_fn_err_a.out

@@ -1,6 +1,6 @@
 vlib/v/checker/tests/array_filter_anon_fn_err_a.vv:2:24: error: function needs exactly 1 argument
     1 | fn main() {
     2 |     a := [1,2,3,4].filter(fn(a int, b int) bool { return a > 0 })
-      |                           ~~
+      |                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     3 |     println(a)
     4 | }

vlib/v/checker/tests/array_filter_anon_fn_err_b.out

@@ -1,6 +1,6 @@
 vlib/v/checker/tests/array_filter_anon_fn_err_b.vv:2:24: error: type mismatch, should use `fn(a int) bool {...}`
     1 | fn main() {
     2 |     a := [1,2,3,4].filter(fn(a string) bool { return a.len > 0 })
-      |                           ~~
+      |                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     3 |     println(a)
     4 | }

vlib/v/checker/tests/array_map_anon_fn_err_a.out

@@ -1,6 +1,6 @@
 vlib/v/checker/tests/array_map_anon_fn_err_a.vv:2:21: error: function needs exactly 1 argument
     1 | fn main() {
     2 |     a := [1,2,3,4].map(fn(a int, b int) int {return a + b})
-      |                        ~~
+      |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     3 |     println(a)
     4 | }

vlib/v/checker/tests/array_map_anon_fn_err_b.out

@@ -1,6 +1,6 @@
 vlib/v/checker/tests/array_map_anon_fn_err_b.vv:2:21: error: type mismatch, should use `fn(a int) T {...}`
     1 | fn main() {
     2 |     a := [1,2,3,4].map(fn(a string) string { return a })
-      |                        ~~
+      |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     3 |     println(a)
     4 | }

vlib/v/checker/tests/array_map_anon_fn_err_c.out

@@ -1,6 +1,6 @@
 vlib/v/checker/tests/array_map_anon_fn_err_c.vv:2:21: error: type mismatch, should use `fn(a int) T {...}`
     1 | fn main() {
     2 |     a := [1,2,3,4].map(fn(a string) {})
-      |                        ~~
+      |                        ~~~~~~~~~~~~~~~
     3 |     println(a)
     4 | }

vlib/v/checker/tests/fn_var.out

@@ -14,4 +14,4 @@ vlib/v/checker/tests/fn_var.vv:5:5: error: cannot assign to `f`: expected `fn (i
     3 | mut p := &f
     4 | p = &[f]
     5 | f = fn(mut a []int) {}
-      |     ~~
+      |     ~~~~~~~~~~~~~~~~~~

vlib/v/parser/fn.v

@@ -439,7 +439,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 }
 
 fn (mut p Parser) anon_fn() ast.AnonFn {
-	mut pos := p.tok.position()
+	pos := p.tok.position()
 	p.check(.key_fn)
 	if p.pref.is_script && p.tok.kind == .name {
 		p.error_with_pos('function declarations in script mode should be before all script statements',
@@ -491,7 +491,6 @@ fn (mut p Parser) anon_fn() ast.AnonFn {
 	idx := p.table.find_or_register_fn_type(p.mod, func, true, false)
 	typ := table.new_type(idx)
 	// name := p.table.get_type_name(typ)
-	pos.update_last_line(p.prev_tok.line_nr)
 	return ast.AnonFn{
 		decl: ast.FnDecl{
 			name: name
@@ -503,7 +502,7 @@ fn (mut p Parser) anon_fn() ast.AnonFn {
 			is_method: false
 			is_anon: true
 			no_body: no_body
-			pos: pos
+			pos: pos.extend(p.prev_tok.position())
 			file: p.file_name
 			scope: p.scope
 		}