[IR] Support if and when for MFVC, fix several bugs, refactor

#KT-1179

compiler/testData/codegen/box/valueClasses/conditionalExpressions.kt

@@ -0,0 +1,53 @@
+// CHECK_BYTECODE_LISTING
+// WITH_STDLIB
+// TARGET_BACKEND: JVM_IR
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses
+
+@JvmInline
+value class DPoint(val x: Double, val y: Double) {
+    init {
+        counter++
+    }
+    companion object {
+        @JvmStatic
+        var counter: Int = 0
+    }
+}
+
+fun ifExpr() = if (DPoint(0.0, 1.0).x > 0.0) DPoint(2.0, 3.0) else DPoint(4.0, 5.0)
+
+fun whenExpr() = when {
+    DPoint(6.0, 7.0).x > 0.0 -> DPoint(8.0, 9.0)
+    DPoint(10.0, 11.0).x > 0.0 -> DPoint(12.0, 13.0)
+    else -> DPoint(14.0, 15.0)
+}
+
+fun ifBody() {
+    if (DPoint(0.0, 1.0).x > 0.0) DPoint(2.0, 3.0) else DPoint(4.0, 5.0)
+    val x = if (DPoint(0.0, 1.0).x > 0.0) DPoint(2.0, 3.0) else DPoint(4.0, 5.0)
+    require(x == DPoint(4.0, 5.0))
+}
+
+fun whenBody() {
+    when {
+        DPoint(6.0, 7.0).x > 0.0 -> DPoint(8.0, 9.0)
+        DPoint(10.0, 11.0).x > 0.0 -> DPoint(12.0, 13.0)
+        else -> DPoint(14.0, 15.0)
+    }
+    val x = when {
+        DPoint(6.0, 7.0).x > 0.0 -> DPoint(8.0, 9.0)
+        DPoint(10.0, 11.0).x > 0.0 -> DPoint(12.0, 13.0)
+        else -> DPoint(14.0, 15.0)
+    }
+    require(x == DPoint(8.0, 9.0))
+}
+
+fun box(): String {
+    ifBody()
+    whenBody()
+    require(ifExpr() == DPoint(4.0, 5.0))
+    require(whenExpr() == DPoint(8.0, 9.0))
+    require(DPoint.counter == 5 + 5 + 2 + 1 + 2 + 1)
+    return "OK"
+}

compiler/testData/codegen/box/valueClasses/conditionalExpressions.txt

@@ -0,0 +1,51 @@
+@kotlin.Metadata
+public final class ConditionalExpressionsKt {
+    // source: 'conditionalExpressions.kt'
+    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
+    public final static method ifBody(): void
+    public final static @org.jetbrains.annotations.NotNull method ifExpr(): DPoint
+    public final static method whenBody(): void
+    public final static @org.jetbrains.annotations.NotNull method whenExpr(): DPoint
+    public final inner class DPoint$Companion
+}
+
+@kotlin.Metadata
+public final class DPoint$Companion {
+    // source: 'conditionalExpressions.kt'
+    private method <init>(): void
+    public synthetic method <init>(p0: kotlin.jvm.internal.DefaultConstructorMarker): void
+    public synthetic deprecated static @kotlin.jvm.JvmStatic method getCounter$annotations(): void
+    public final method getCounter(): int
+    public final method setCounter(p0: int): void
+    public final inner class DPoint$Companion
+}
+
+@kotlin.jvm.JvmInline
+@kotlin.Metadata
+public final class DPoint {
+    // source: 'conditionalExpressions.kt'
+    public final static @org.jetbrains.annotations.NotNull field Companion: DPoint$Companion
+    private static field counter: int
+    private final field field-0: double
+    private final field field-1: double
+    static method <clinit>(): void
+    private synthetic method <init>(p0: double, p1: double): void
+    public synthetic final static method access$getCounter$cp(): int
+    public synthetic final static method access$setCounter$cp(p0: int): void
+    public synthetic final static method box-impl(p0: double, p1: double): DPoint
+    public final static method constructor-impl(p0: double, p1: double): void
+    public method equals(@org.jetbrains.annotations.Nullable p0: java.lang.Object): boolean
+    public static method equals-impl(p0: double, p1: double, p2: java.lang.Object): boolean
+    public final static method equals-impl0(p0: double, p1: double, p2: double, p3: double): boolean
+    public final static method getCounter(): int
+    public final static method getX-impl(p0: double, p1: double): double
+    public final static method getY-impl(p0: double, p1: double): double
+    public method hashCode(): int
+    public static method hashCode-impl(p0: double, p1: double): int
+    public final static method setCounter(p0: int): void
+    public @org.jetbrains.annotations.NotNull method toString(): java.lang.String
+    public static method toString-impl(p0: double, p1: double): java.lang.String
+    public synthetic final method unbox-impl-0(): double
+    public synthetic final method unbox-impl-1(): double
+    public final inner class DPoint$Companion
+}

compiler/testData/codegen/box/valueClasses/visibility.txt

@@ -26,6 +26,7 @@ public final class Internal {
     public final static @org.jetbrains.annotations.NotNull field Companion: Internal$Companion
     private final field field-0: int
     private final field field-1: int
+    private static field x: int
     static method <clinit>(): void
     private synthetic method <init>(p0: int, p1: int): void
     public synthetic final static method access$getX$cp(): int
@@ -228,6 +229,7 @@ public final class Public {
     public final static @org.jetbrains.annotations.NotNull field Companion: Public$Companion
     private final field field-0: int
     private final field field-1: int
+    private static field x: int
     static method <clinit>(): void
     private synthetic method <init>(p0: int, p1: int): void
     public synthetic final static method access$getX$cp(): int