Get rid of 'class object' usages in code and builtins

Replace some comments and library usages as well

core/builtins/native/kotlin/Enum.kt

@@ -22,7 +22,7 @@ package kotlin
  * information on enum classes.
  */
 public abstract class Enum<E : Enum<E>>(name: String, ordinal: Int): Comparable<E> {
-    class object Companion {}
+    companion object {}
 
     /**
      * Returns the name of this enum constant, exactly as declared in its enum declaration.

core/builtins/native/kotlin/Primitives.kt

@@ -23,7 +23,7 @@ package kotlin
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `byte`.
  */
 public class Byte private () : Number, Comparable<Byte> {
-    class object Companion {}
+    companion object {}
 
 /**
  * Compares this value with the specified value for order.
@@ -181,7 +181,7 @@ public class Byte private () : Number, Comparable<Byte> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `char`.
  */
 public class Char private () : Comparable<Char> {
-    class object Companion {}
+    companion object {}
 
 /**
  * Compares the character code of this character with the specified value for order.
@@ -326,7 +326,7 @@ public class Char private () : Comparable<Char> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `short`.
  */
 public class Short private () : Number, Comparable<Short> {
-    class object Companion {}
+    companion object {}
 
 /**
  * Compares this value with the specified value for order.
@@ -484,7 +484,7 @@ public class Short private () : Number, Comparable<Short> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `int`.
  */
 public class Int private () : Number, Comparable<Int> {
-    class object Companion {}
+    companion object {}
 
 /**
  * Compares this value with the specified value for order.
@@ -657,7 +657,7 @@ public class Int private () : Number, Comparable<Int> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `long`.
  */
 public class Long private () : Number, Comparable<Long> {
-    class object Companion {}
+    companion object {}
 
 /**
  * Compares this value with the specified value for order.
@@ -830,7 +830,7 @@ public class Long private () : Number, Comparable<Long> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `float`.
  */
 public class Float private () : Number, Comparable<Float> {
-    class object Companion : FloatingPointConstants<Float> {}
+    companion object : FloatingPointConstants<Float> {}
 
 /**
  * Compares this value with the specified value for order.
@@ -988,7 +988,7 @@ public class Float private () : Number, Comparable<Float> {
  * On the JVM, non-nullable values of this type are represented as values of the primitive type `double`.
  */
 public class Double private () : Number, Comparable<Double> {
-    class object Companion : FloatingPointConstants<Double> {}
+    companion object : FloatingPointConstants<Double> {}
 
 /**
  * Compares this value with the specified value for order.

core/builtins/native/kotlin/String.kt

@@ -21,7 +21,7 @@ package kotlin
  * implemented as instances of this class.
  */
 public class String : Comparable<String>, CharSequence {
-    class object Companion {}
+    companion object {}
     
     /**
      * Returns a string obtained by concatenating this string with the string representation of the given [other] object.

core/builtins/src/kotlin/Ranges.kt

@@ -38,7 +38,7 @@ public class ByteRange(override val start: Byte, override val end: Byte) : Range
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * start.toInt() + end)
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Byte. */
         public val EMPTY: ByteRange = ByteRange(1, 0)
     }
@@ -64,7 +64,7 @@ public class CharRange(override val start: Char, override val end: Char) : Range
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * start.toInt() + end)
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Char. */
         public val EMPTY: CharRange = CharRange(1.toChar(), 0.toChar())
     }
@@ -90,7 +90,7 @@ public class ShortRange(override val start: Short, override val end: Short) : Ra
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * start.toInt() + end)
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Short. */
         public val EMPTY: ShortRange = ShortRange(1, 0)
     }
@@ -116,7 +116,7 @@ public class IntRange(override val start: Int, override val end: Int) : Range<In
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * start + end)
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Int. */
         public val EMPTY: IntRange = IntRange(1, 0)
     }
@@ -142,7 +142,7 @@ public class LongRange(override val start: Long, override val end: Long) : Range
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * (start xor (start ushr 32)) + (end xor (end ushr 32))).toInt()
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Long. */
         public val EMPTY: LongRange = LongRange(1, 0)
     }
@@ -168,7 +168,7 @@ public class FloatRange(override val start: Float, override val end: Float) : Ra
     override fun hashCode(): Int =
         if (isEmpty()) -1 else (31 * java.lang.Float.floatToIntBits(start) + java.lang.Float.floatToIntBits(end))
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Float. */
         public val EMPTY: FloatRange = FloatRange(1.0f, 0.0f)
     }
@@ -199,7 +199,7 @@ public class DoubleRange(override val start: Double, override val end: Double) :
         return (31 * result + (temp xor (temp ushr 32))).toInt()
     }
 
-    class object Companion {
+    companion object {
         /** An empty range of values of type Double. */
         public val EMPTY: DoubleRange = DoubleRange(1.0, 0.0)
     }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/components/SamConversionResolver.kt

@@ -25,7 +25,7 @@ import org.jetbrains.kotlin.resolve.scopes.JetScope
 import org.jetbrains.kotlin.types.JetType
 
 public trait SamConversionResolver {
-    public class object EMPTY : SamConversionResolver {
+    public companion object EMPTY : SamConversionResolver {
         override fun <D : FunctionDescriptor> resolveSamAdapter(original: D) = null
         override fun resolveSamConstructor(name: Name, scope: JetScope) = null
         override fun resolveFunctionTypeIfSamInterface(

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/MemberSignature.kt

@@ -22,7 +22,7 @@ import org.jetbrains.kotlin.name.Name
 // The purpose of this class is to hold a unique signature of either a method or a field, so that annotations on a member can be put
 // into a map indexed by these signatures
 data class MemberSignature private(private val signature: String) {
-    class object {
+    companion object {
         platformStatic public fun fromMethodNameAndDesc(nameAndDesc: String): MemberSignature {
             return MemberSignature(nameAndDesc)
         }

core/descriptors.runtime/src/org/jetbrains/kotlin/load/java/structure/reflect/ReflectJavaAnnotationArguments.kt

@@ -22,7 +22,7 @@ import org.jetbrains.kotlin.name.Name
 abstract class ReflectJavaAnnotationArgument(
         override val name: Name?
 ) : JavaAnnotationArgument {
-    class object Factory {
+    companion object Factory {
         fun create(value: Any, name: Name?): ReflectJavaAnnotationArgument {
             return when {
                 value.javaClass.isEnumClassOrSpecializedEnumEntryClass() -> ReflectJavaEnumValueAnnotationArgument(name, value as Enum<*>)

core/descriptors.runtime/src/org/jetbrains/kotlin/load/java/structure/reflect/ReflectJavaType.kt

@@ -27,7 +27,7 @@ public abstract class ReflectJavaType : JavaType {
 
     override fun createArrayType(): JavaArrayType = throw UnsupportedOperationException()
 
-    class object Factory {
+    companion object Factory {
         fun create(type: Type): ReflectJavaType {
             return when {
                 type is Class<*> && type.isPrimitive() -> ReflectJavaPrimitiveType(type)

core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/ReflectKotlinClass.kt

@@ -44,7 +44,7 @@ public class ReflectKotlinClass private(
         private val classHeader: KotlinClassHeader
 ) : KotlinJvmBinaryClass {
 
-    class object Factory {
+    companion object Factory {
 
         public fun create(klass: Class<*>): ReflectKotlinClass? {
             val headerReader = ReadKotlinClassHeaderAnnotationVisitor()

core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/RuntimeModuleData.kt

@@ -29,7 +29,7 @@ public class RuntimeModuleData private(private val injector: InjectorForRuntimeD
 
     public val localClassResolver: LocalClassResolver get() = injector.getDeserializationComponentsForJava().components.localClassResolver
 
-    class object {
+    companion object {
         public fun create(classLoader: ClassLoader): RuntimeModuleData {
             val module = ModuleDescriptorImpl(Name.special("<runtime module for $classLoader>"), listOf(), JavaToKotlinClassMap.INSTANCE)
             module.addDependencyOnModule(module)

core/descriptors/src/org/jetbrains/kotlin/descriptors/annotations/Annotations.kt

@@ -26,7 +26,7 @@ public trait Annotations : Iterable<AnnotationDescriptor> {
 
     public fun findAnnotation(fqName: FqName): AnnotationDescriptor?
 
-    class object {
+    companion object {
         public val EMPTY: Annotations = object : Annotations {
             override fun isEmpty() = true
 

core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/JetScope.kt

@@ -76,7 +76,7 @@ public trait JetScope {
         }
     }
 
-    class object {
+    companion object {
         public val ALL_NAME_FILTER: (Name) -> Boolean = { true }
     }
 }
@@ -141,7 +141,7 @@ public class DescriptorKindFilter(
         }
     }
 
-    class object {
+    companion object {
         public val NON_SINGLETON_CLASSIFIERS_MASK: Int = 0x01
         public val SINGLETON_CLASSIFIERS_MASK: Int = 0x02
         public val PACKAGES_MASK: Int = 0x04

core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt

@@ -33,7 +33,7 @@ public trait FlexibleTypeCapabilities {
 }
 
 public trait Flexibility : TypeCapability, SubtypingRepresentatives {
-    class object {
+    companion object {
         // This is a "magic" classifier: when type resolver sees it in the code, e.g. ft<Foo, Foo?>, instead of creating a normal type,
         // it creates a flexible type, e.g. (Foo..Foo?).
         // This is used in tests and Evaluate Expression to have flexible types in the code,
@@ -145,7 +145,7 @@ public open class DelegatingFlexibleType protected (
         override val upperBound: JetType,
         override val extraCapabilities: FlexibleTypeCapabilities
 ) : DelegatingType(), NullAwareness, Flexibility, FlexibleTypeDelegation, Approximation {
-    class object {
+    companion object {
         platformStatic fun create(lowerBound: JetType, upperBound: JetType, extraCapabilities: FlexibleTypeCapabilities): JetType {
             if (lowerBound == upperBound) return lowerBound
             return DelegatingFlexibleType(lowerBound, upperBound, extraCapabilities)