Reserve yield if it isn't function call.

compiler/testData/diagnostics/tests/ReserveYield.kt

@@ -0,0 +1,70 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION -UNREACHABLE_CODE -UNUSED_VARIABLE
+
+// FILE: 1.kt
+package p1.yield
+
+import p1.yield.yield
+import p1.yield.foo
+
+val yield = 5
+fun foo(){}
+
+fun bar(yield: Int = 4) {}
+
+fun yield(yield: Int) {
+    "$<!YIELD_IS_RESERVED!>yield<!>"
+    "${<!YIELD_IS_RESERVED!>yield<!>}"
+
+    <!YIELD_IS_RESERVED!>yield<!>
+    val foo = <!YIELD_IS_RESERVED!>yield<!> + <!YIELD_IS_RESERVED!>yield<!>
+    val foo2 = <!YIELD_IS_RESERVED!>yield<!>
+
+    bar(<!YIELD_IS_RESERVED!>yield<!> = 5)
+
+    yield(4)
+    <!YIELD_IS_RESERVED!>yield<!> {}
+
+    class yield<T: <!YIELD_IS_RESERVED!>yield<!><T>>
+
+    return@<!YIELD_IS_RESERVED!>yield<!>
+    return@<!YIELD_IS_RESERVED!>yield<!> Unit
+
+    val foo5: <!YIELD_IS_RESERVED!>yield<!><*>
+}
+
+fun yield(i: (Int) -> Unit) {}
+
+// FILE: 2.kt
+
+package p2.yield
+
+import p2.yield.yield
+import p2.yield.foo
+
+val yield = 5
+fun foo(){}
+
+fun bar(yield: Int = 4) {}
+
+fun yield(yield: Int) {
+    "$`yield`"
+    "${`yield`}"
+
+    `yield`
+    val foo = `yield` + `yield`
+    val foo2 = `yield`
+
+    bar(`yield` = 5)
+
+    `yield`(4)
+    `yield` {}
+
+    class `yield`<T: `yield`<T>>
+
+    return@`yield`
+    return@`yield` Unit
+
+    val foo5: `yield`<*>
+}
+
+fun yield(i: (Int) -> Unit) {}

compiler/testData/diagnostics/tests/ReserveYield.txt

@@ -0,0 +1,23 @@
+package
+
+package p1 {
+
+    package p1.yield {
+        public val yield: kotlin.Int = 5
+        public fun bar(/*0*/ yield: kotlin.Int = ...): kotlin.Unit
+        public fun foo(): kotlin.Unit
+        public fun yield(/*0*/ i: (kotlin.Int) -> kotlin.Unit): kotlin.Unit
+        public fun yield(/*0*/ yield: kotlin.Int): kotlin.Unit
+    }
+}
+
+package p2 {
+
+    package p2.yield {
+        public val yield: kotlin.Int = 5
+        public fun bar(/*0*/ yield: kotlin.Int = ...): kotlin.Unit
+        public fun foo(): kotlin.Unit
+        public fun yield(/*0*/ i: (kotlin.Int) -> kotlin.Unit): kotlin.Unit
+        public fun yield(/*0*/ yield: kotlin.Int): kotlin.Unit
+    }
+}

compiler/testData/diagnostics/tests/ReserveYield2.kt

@@ -0,0 +1,54 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION -UNREACHABLE_CODE -UNUSED_VARIABLE -WRONG_ANNOTATION_TARGET -UNUSED_LAMBDA_EXPRESSION
+
+// FILE: 1.kt
+
+annotation class yield
+
+fun bar(p: Int) {
+    <!YIELD_IS_RESERVED!>yield<!>@ p
+    `yield`@ p
+
+    @<!YIELD_IS_RESERVED!>yield<!>() p
+    @`yield`() p
+
+    for (yield in 1..5) {
+
+    }
+    { yield: Int -> }
+
+    val (yield) = listOf(4)
+
+}
+
+fun <T> listOf(vararg e: T): List<T> = null!!
+operator fun <T> List<T>.component1() = get(0)
+
+// FILE: 2.kt
+package p3
+
+enum class yield {
+    yield
+}
+
+fun f1(yield: Int, foo: Int = <!YIELD_IS_RESERVED!>yield<!>) {}
+
+fun f2(foo: <!YIELD_IS_RESERVED!>yield<!>) {}
+
+// FILE: 3.kt
+package p4
+
+typealias yield = Number
+
+fun <yield: Number> f1() {}
+fun <y: <!YIELD_IS_RESERVED!>yield<!>> f2() {}
+
+// FILE: 4.kt
+object X {
+    fun yield() {}
+
+    fun test3(yield: Int) {
+        X::<!YIELD_IS_RESERVED!>yield<!>
+
+        <!YIELD_IS_RESERVED!>yield<!>::toInt
+    }
+}

compiler/testData/diagnostics/tests/ReserveYield2.txt

@@ -0,0 +1,51 @@
+package
+
+public fun bar(/*0*/ p: kotlin.Int): kotlin.Unit
+public fun </*0*/ T> listOf(/*0*/ vararg e: T /*kotlin.Array<out T>*/): kotlin.collections.List<T>
+public operator fun </*0*/ T> kotlin.collections.List<T>.component1(): T
+
+public object X {
+    private constructor X()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun test3(/*0*/ yield: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public final fun yield(): kotlin.Unit
+}
+
+public final annotation class yield : kotlin.Annotation {
+    public constructor yield()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+package p3 {
+    public fun f1(/*0*/ yield: kotlin.Int, /*1*/ foo: kotlin.Int = ...): kotlin.Unit
+    public fun f2(/*0*/ foo: p3.yield): kotlin.Unit
+
+    public final enum class yield : kotlin.Enum<p3.yield> {
+        enum entry yield
+
+        private constructor yield()
+        public final override /*1*/ /*fake_override*/ val name: kotlin.String
+        public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+        protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+        public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: p3.yield): kotlin.Int
+        public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun finalize(): kotlin.Unit
+        public final override /*1*/ /*fake_override*/ /*isHiddenForResolutionEverywhereBesideSupercalls*/ fun getDeclaringClass(): java.lang.Class<p3.yield!>!
+        public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        // Static members
+        public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): p3.yield
+        public final /*synthesized*/ fun values(): kotlin.Array<p3.yield>
+    }
+}
+
+package p4 {
+    public fun </*0*/ yield : kotlin.Number> f1(): kotlin.Unit
+    public fun </*0*/ y : p4.yield /* = kotlin.Number */> f2(): kotlin.Unit
+    public typealias yield = kotlin.Number
+}