$clinit_Boolean is not always optimized out when empty

[niloc132]

GWT version: 2.12.1, latest
Browser (with version): any
Operating System: any

---

Description

While most empty clinits seem to be correctly optimized out, sometimes they unnecessarily remain in the compiled output.

As an example, if you build https://github.com/gwtproject/gwt-site-webapp/ but change turn draft mode off, $clinit_Object is correctly removed, but $clinit_Boolean is not, despite being empty:

function $clinit_Boolean(){
  $clinit_Boolean = emptyMethod;
}

A Java lambda of type elemental2.core.ReadonlyArray.FindPredicateFn

(el, index, parent) -> !"none".equals(((HTMLElement) el).style.display)

is translated as

function GWTProjectEntryPoint$lambda$9$Type(){
}

defineClass(81, $wnd.Function, {}, GWTProjectEntryPoint$lambda$9$Type);
_.onInvoke_2 = function onInvoke_5(arg0, arg1, arg2){
  return $clinit_GWTProjectEntryPoint() , $clinit_Boolean() , $equals('none', castToNative(arg0, $wnd.HTMLElement).style.display)?false:true;
}
;

which looks like boxing of boolean to Boolean via inlining Boolean.valueOf(boolean) gone a bit wrong:

gwt/user/super/com/google/gwt/emul/java/lang/Boolean.java

Lines 63 to 65 in c2229e7

	public static Boolean valueOf(boolean b) {
	return b ? $create(true) : $create(false);
	}

  private boolean shouldEnhanceLink(Element link) {
    return
        // Enhance only local links
        isSameOriginRexp.test(link.getAttribute("href"))
        // Do not load links that are marked as full page reload
        && !Boolean.parseBoolean(link.getAttribute("data-full-load"));
  }

is inlined into two different places, bringing Boolean.parseBoolean with it:

function $lambda$16(this$static, evt_0){
  //...
  if ($test(isSameOriginRexp, target.getAttribute('href')) && ($clinit_Boolean() , !$equalsIgnoreCase('true', target.getAttribute('data-full-load'))) && $handleAsClick(castToNative(evt_0, $wnd.MouseEvent))) {
    //...
  }
}

function $lambda$19(el_0){
  //...
  if ($test(isSameOriginRexp, el_0.getAttribute('href')) && ($clinit_Boolean() , !$equalsIgnoreCase('true', el_0.getAttribute('data-full-load')))) {
    //...
  }
}

gwt/user/super/com/google/gwt/emul/java/lang/Boolean.java

Lines 55 to 57 in c2229e7

	public static boolean parseBoolean(String s) {
	return "true".equalsIgnoreCase(s);
	}

Steps to reproduce

Check out gwt-site-webapp @ 27070768ae49c048535358a03c70a5b9d84ddf98

git clone [email protected]:gwtproject/gwt-site-webapp.git
cd gwt-site-webapp
git checkout 27070768ae49c048535358a03c70a5b9d84ddf98

Change draft compile to false

diff --git a/pom.xml b/pom.xml
index 747c5b2..f8fc02e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -81,7 +81,7 @@
                     <compilerArgs>
                         <arg>-saveSource</arg>
                     </compilerArgs>
-                    <draftCompile>true</draftCompile>
+                    <draftCompile>false</draftCompile>
                     <style>PRETTY</style>
                     <failOnError>true</failOnError>
                     <launcherDir>${project.build.directory}/www</launcherDir>

Build the project, with mvn clean verify

Expected: If $clinit_Boolean is present, it is non-empty.
Actual: $clinit_Boolean is present, and only reassigns itself to emptyMethod