map: rename size to len

cmd/tools/check_os_api_parity.v

@@ -55,7 +55,7 @@ fn main() {
 			app.compare_api(api_base, api_os, mname, base_os, oname)
 		}
 	}
-	howmany := app.api_differences.size
+	howmany := app.api_differences.len
 	eprintln('NB: please, do run `git clean -xf` after this tool, or at least `find thirdparty/ |grep .o$|xargs rm`')
 	eprintln('otherwise, `./v test-fixed` may show false positives, due to .o files compiled with a cross compiler.')
 	if howmany > 0 {

cmd/tools/vdoc.v

@@ -686,7 +686,7 @@ fn (mut cfg DocConfig) generate_docs_from_file() {
 	cfg.vprintln('Rendering docs...')
 	if cfg.output_path.len == 0 {
 		outputs := cfg.render()
-		if outputs.size == 0 {
+		if outputs.len == 0 {
 			println('No documentation for $dirs')
 		} else {
 			first := outputs.keys()[0]