NI: don't try to infer visible lambda parameters, if there is single one – extension parameter

^KT-37038 Fixed

compiler/testData/diagnostics/tests/inference/extensionLambdasAndArrow.fir.kt

@@ -0,0 +1,10 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_ANONYMOUS_PARAMETER
+
+fun main() {
+    val x1: String.() -> String = if (true) {{ this }} else {{ this }}
+    val x2: String.() -> String = if (true) {{ -> this }} else {{ -> this }}
+    val x3: () -> String = if (true) {{ -> "this" }} else {{ -> "this" }}
+    val x4: String.() -> String = if (true) {{ str: String -> "this" }} else {{ str: String -> "this" }}
+    val x5: String.() -> String = if (true) {{ str -> "this" }} else {{ str -> "this" }}
+    val x6: String.() -> String = if (true) {{ str -> "this" }} else {{ "this" }}
+}

compiler/testData/diagnostics/tests/inference/extensionLambdasAndArrow.kt

@@ -0,0 +1,14 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_ANONYMOUS_PARAMETER
+
+fun <T> select(vararg x: T) = x[0]
+
+fun main() {
+    val x1: String.() -> String = if (true) {{ this }} else {{ this }}
+    val x2: String.() -> String = if (true) {{ -> this }} else {{ -> this }}
+    val x3: () -> String = if (true) {{ -> "this" }} else {{ -> "this" }}
+    val x4: String.() -> String = if (true) {{ str: String -> "this" }} else {{ str: String -> "this" }}
+    val x5: String.() -> String = if (true) <!TYPE_MISMATCH!>{{ <!CANNOT_INFER_PARAMETER_TYPE, EXPECTED_PARAMETERS_NUMBER_MISMATCH!>str<!> -> "this" }}<!> else <!TYPE_MISMATCH!>{{ <!CANNOT_INFER_PARAMETER_TYPE, EXPECTED_PARAMETERS_NUMBER_MISMATCH!>str<!> -> "this" }}<!>
+    val x6: String.() -> String = if (true) <!TYPE_MISMATCH!>{{ <!CANNOT_INFER_PARAMETER_TYPE, EXPECTED_PARAMETERS_NUMBER_MISMATCH!>str<!> -> "this" }}<!> else {{ "this" }}
+    val x7: String.() -> String = select({ -> this }, { -> this })
+    val x8: String.() -> String = select({ this }, { this })
+}

compiler/testData/diagnostics/tests/inference/extensionLambdasAndArrow.txt

@@ -0,0 +1,3 @@
+package
+
+public fun main(): kotlin.Unit