Fix ParseError on CSS variable when there is no trailing semicolon

see less/less.js#3700

Bug: T386077
Change-Id: I60c0ddad9a85409b6b2ac5ecf3fab00cd8876157

Author: anny21

lib/Less/Parser.php

@@ -2452,7 +2452,7 @@ private function parseDeclaration() {
 				if ( is_array( $name ) && array_key_exists( 0, $name ) // to satisfy phan
 					&& $name[0] instanceof Less_Tree_Keyword
 					&& $name[0]->value && strpos( $name[0]->value, '--' ) === 0 ) {
-					$value = $this->parsePermissiveValue();
+					$value = $this->parsePermissiveValue( [ ';', '}' ] );
 				} else {
 					// Try to store values as anonymous
 					// If we need the value later we'll re-parse it in ruleset.parseValue

test/Fixtures/less.php/css/T386077-no-trailing-semicolon.css

@@ -0,0 +1,8 @@
+.test {
+  --test: 38px;
+}
+@media only screen and (max-width: 1024px) {
+  .test {
+    --test: 38px;
+  }
+}

test/Fixtures/less.php/less/T386077-no-trailing-semicolon.less

@@ -0,0 +1,9 @@
+.test {
+    --test: 38px
+}
+
+.test {
+  @media only screen and (max-width: 1024px) {
+       --test: 38px
+   }
+}