[FIR] Implement Int -> Long conversions for literals and operators over them

^KT-38895
^KT-50996 Fixed
^KT-51000 Fixed
^KT-51003 Fixed
^KT-51018 Fixed

compiler/testData/diagnostics/tests/integerLiterals/literalsInInference.kt

@@ -0,0 +1,24 @@
+// FIR_IDENTICAL
+// ISSUE: KT-51003
+
+interface Assert<T>
+
+fun <T> createAssert(value: T): Assert<T> = null!!
+
+fun <A, B : Comparable<A>> Assert<B>.isGreaterThanOrEqualTo(other: A) {}
+
+fun test_1(long: Long) {
+    // FE 1.0: OK
+    // FIR: ARGUMENT_TYPE_MISMATCH
+    createAssert(long).isGreaterThanOrEqualTo(10 * 10)
+}
+
+fun getNullableLong(): Long? = null
+fun takeLong(x: Long) {}
+
+fun test_2() {
+    val x = getNullableLong() ?: 10 * 60
+    takeLong(x)
+    // FE 1.0 infers type of `x` to `Long`
+    // FIR infers it to `Number` as `CST(Long, Int)`
+}