Fix annotation processor builder setter detection

Update TypeElementMembers to correctly detect builder style setters.
The previous logic could fail because of the crazy way that TypeMirror
implements its equals() method.

Fixes gh-1859
See gh-1854

spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/TypeElementMembers.java

@@ -95,8 +95,9 @@ class TypeElementMembers {
 	}
 
 	private boolean isSetterReturnType(ExecutableElement method) {
-		return (TypeKind.VOID == method.getReturnType().getKind() || method
-				.getEnclosingElement().asType().equals(method.getReturnType()));
+		return (TypeKind.VOID == method.getReturnType().getKind() || this.env
+				.getTypeUtils().isSameType(method.getEnclosingElement().asType(),
+						method.getReturnType()));
 	}
 
 	private String getAccessorName(String methodName) {