KT-45777: Remove proto-based approach to compute Java class snapshots

as the ASM-based approach is better, and we have switched to the
ASM-based approach for a while now.

compiler/resolution.common.jvm/src/org/jetbrains/kotlin/load/java/structure/impl/classFiles/BinaryJavaClass.kt

@@ -32,15 +32,13 @@ import java.text.CharacterIterator
 import java.text.StringCharacterIterator
 
 class BinaryJavaClass(
-    /** If virtualFile is not available, provide classContent & innerClassFinder below. */
-    override val virtualFile: VirtualFile? = null,
+    override val virtualFile: VirtualFile,
     override val fqName: FqName,
     internal val context: ClassifierResolutionContext,
     private val signatureParser: BinaryClassSignatureParser,
     override var access: Int = 0,
     override val outerClass: JavaClass?,
-    classContent: ByteArray? = null,
-    private val innerClassFinder: ((Name) -> JavaClass?)? = null
+    classContent: ByteArray? = null
 ) : ClassVisitor(ASM_API_VERSION_FOR_CLASS_READING), VirtualFileBoundJavaClass, BinaryJavaModifierListOwner, MutableJavaAnnotationOwner {
     override val annotations: MutableCollection<JavaAnnotation> = SmartList()
 
@@ -113,17 +111,13 @@ class BinaryJavaClass(
     }
 
     init {
-        if (virtualFile == null) {
-            checkNotNull(classContent) { "classContent must be provided when virtualFile is not available" }
-            checkNotNull(innerClassFinder) { "innerClassFinder must be provided when virtualFile is not available" }
-        }
         try {
-            ClassReader(classContent ?: virtualFile!!.contentsToByteArray()).accept(
+            ClassReader(classContent ?: virtualFile.contentsToByteArray()).accept(
                 this,
                 ClassReader.SKIP_CODE or ClassReader.SKIP_FRAMES
             )
         } catch (e: Throwable) {
-            throw IllegalStateException("Could not read class " + (virtualFile ?: ""), e)
+            throw IllegalStateException("Could not read class: $virtualFile", e)
         }
     }
 
@@ -253,15 +247,11 @@ class BinaryJavaClass(
     fun findInnerClass(name: Name, classFileContent: ByteArray?): JavaClass? {
         val access = ownInnerClassNameToAccess[name] ?: return null
 
-        return if (virtualFile != null) {
-            virtualFile.parent.findChild("${virtualFile.nameWithoutExtension}$$name.class")?.let {
-                BinaryJavaClass(
-                    it, fqName.child(name), context.copyForMember(), signatureParser, access, this,
-                    classFileContent
-                )
-            }
-        } else {
-            innerClassFinder!!(name)
+        return virtualFile.parent.findChild("${virtualFile.nameWithoutExtension}$$name.class")?.let {
+            BinaryJavaClass(
+                it, fqName.child(name), context.copyForMember(), signatureParser, access, this,
+                classFileContent
+            )
         }
     }