FIR: Do not run completion for lambda's explicit return too early

See the test case
Completion for synthetic call: x ?: return@myRun materialize()
makes `materialize()` while it's obviously too early for that

compiler/fir/analysis-tests/testData/resolve/inference/lambdasReturns.fir.txt

@@ -0,0 +1,15 @@
+FILE: lambdasReturns.kt
+    public final fun <R> myRun(b: R|() -> R|): R|R| {
+        ^myRun R|<local>/b|.R|SubstitutionOverride<kotlin/Function0.invoke: R|R|>|()
+    }
+    public final fun <T> materialize(): R|T| {
+        ^materialize R|kotlin/TODO|()
+    }
+    public final fun foo(x: R|kotlin/String?|): R|kotlin/Unit| {
+        lval r: R|kotlin/Int| = R|/myRun|<R|kotlin/Int|>(<L> = myRun@fun <anonymous>(): R|kotlin/Int| {
+            lval y: R|kotlin/String| = R|<local>/x| ?: ^@myRun R?C|/materialize|()
+            ^ R|<local>/y|.R|kotlin/String.length|
+        }
+        )
+        R|<local>/r|.R|kotlin/Int.minus|(Int(1))
+    }

compiler/fir/analysis-tests/testData/resolve/inference/lambdasReturns.kt

@@ -0,0 +1,15 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+// !WITH_NEW_INFERENCE
+
+fun <R> myRun(b: () -> R): R = b()
+
+fun <T> materialize(): T = TODO()
+
+fun foo(x: String?) {
+    val r = myRun {
+        val y = x ?: return@myRun materialize()
+        y.length
+    }
+
+    r.minus(1)
+}