Relax multiple segment matching constraints in PathPattern

Prior to this commit, gh-35213 allowed wildcard path elments at the
start of path patterns. This came with an additional constraint that
rejected such patterns if the pattern segment following the wildcard one
was not a literal:

* `/**/{name}` was rejected
* `/**/something/{name}` was accepted

The motivation here was to make the performance impact of wildard
patterns as small as possible at runtime.

This commit relaxes this constraint because `/**/*.js` patterns are very
popular in the security space for request matchers.

Closes gh-35686

spring-web/src/test/java/org/springframework/web/util/pattern/PathPatternParserTests.java

@@ -232,7 +232,6 @@ class PathPatternParserTests {
 			checkError("/{abc}{*foobar}", 1, PatternMessage.CAPTURE_ALL_IS_STANDALONE_CONSTRUCT);
 			checkError("/{abc}{*foobar}{foo}", 1, PatternMessage.CAPTURE_ALL_IS_STANDALONE_CONSTRUCT);
 			checkError("/{*foo}/foo/{*bar}", 18, PatternMessage.CANNOT_HAVE_MANY_MULTISEGMENT_PATHELEMENTS);
-			checkError("/{*foo}/{bar}", 8, PatternMessage.MULTISEGMENT_PATHELEMENT_NOT_FOLLOWED_BY_LITERAL);
 			checkError("{foo:}", 5, PatternMessage.MISSING_REGEX_CONSTRAINT);
 			checkError("{foo}_{foo}", 0, PatternMessage.ILLEGAL_DOUBLE_CAPTURE, "foo");
 			checkError("/{bar}/{bar}", 7, PatternMessage.ILLEGAL_DOUBLE_CAPTURE, "bar");

spring-web/src/test/java/org/springframework/web/util/pattern/PathPatternTests.java

@@ -185,6 +185,16 @@ class PathPatternTests {
 			checkMatches("/resource/**", "/resource/foobar");
 		}
 
+		@Test
+		void wildcardSegmentsThenNonLiteral() {
+			checkMatches("/**/*.js", "/script.js");
+			checkMatches("/**/*.js", "/js/script.js");
+			checkMatches("/**/*.js", "/files/js/script.js");
+			checkMatches("/**/{type}/*.js", "/files/js/script.js");
+
+			checkNoMatch("/**/*.js", "/files/style.css");
+		}
+
 		@Test
 		void antPathMatcherTests() {
 			// test exact matching