checker: fix nested struct reference type field initialized check. (fix: #15741) (#15752)

vlib/toml/checker/checker.v

@@ -19,7 +19,7 @@ const utf8_max = 0x10FFFF
 
 // Checker checks a tree of TOML `ast.Value`'s for common errors.
 pub struct Checker {
-	scanner &scanner.Scanner
+	scanner &scanner.Scanner = unsafe { nil }
 }
 
 // check checks the `ast.Value` and all it's children

vlib/toml/decoder/decoder.v

@@ -16,7 +16,7 @@ const (
 
 // Decoder decode special sequences in a tree of TOML `ast.Value`'s.
 pub struct Decoder {
-	scanner &scanner.Scanner
+	scanner &scanner.Scanner = unsafe { nil }
 }
 
 // decode decodes certain `ast.Value`'s and all it's children.

vlib/toml/parser/parser.v

@@ -51,7 +51,7 @@ pub struct Parser {
 pub:
 	config Config
 mut:
-	scanner   &scanner.Scanner
+	scanner   &scanner.Scanner = unsafe { nil }
 	prev_tok  token.Token
 	tok       token.Token
 	peek_tok  token.Token
@@ -75,7 +75,7 @@ mut:
 // `decode_values` is used to en- or disable decoding of values with the `decoder.Decoder`.
 pub struct Config {
 pub:
-	scanner       &scanner.Scanner
+	scanner       &scanner.Scanner = unsafe { nil }
 	run_checks    bool = true
 	decode_values bool = true
 }

vlib/toml/toml.v

@@ -66,7 +66,7 @@ pub:
 // A document can be constructed from a `string` buffer or from a file path
 pub struct Doc {
 pub:
-	ast &ast.Root
+	ast &ast.Root = unsafe { nil }
 }
 
 // parse_file parses the TOML file in `path`.