JVM_IR: fix primitive comparison optimizations

1. the `primitive == object?.something` fusion should not apply to
    `primitive.equals(object?.something)` because it can't;

 2. coercions to Int are there for a reason - don't remove them;

 3. better optimize `primitive == object?.something` -- the result
    should be subject to if-null fusion, so it needs to have a specific
    pattern that resembles safe calls.

 #KT-47597 Fixed

compiler/testData/codegen/box/binaryOp/eqNullableShortToShort.kt

@@ -0,0 +1,7 @@
+class C(val x: Short)
+
+fun box(): String {
+    val a: C = C(1)
+    val b: C? = C(1)
+    return if (b?.x == a.x) "OK" else "fail"
+}

compiler/testData/codegen/box/binaryOp/eqNullableToPrimitiveWithSideEffects.kt

@@ -0,0 +1,19 @@
+// IGNORE_BACKEND: JS, JS_IR, WASM, NATIVE
+var result = ""
+
+fun sideEffecting(): Int {
+    result += "OK"
+    return 123
+}
+
+class C(val x: Int)
+
+val a: C? = C(123)
+val b: C? = null
+
+fun box(): String {
+    if (a?.x != sideEffecting()) return "fail cmp 1"
+    // RHS not evaluated because `b` is null, might be a bug:
+    if (b?.x == sideEffecting()) return "fail cmp 2"
+    return result
+}

compiler/testData/codegen/box/binaryOp/primitiveEqualsSafeCall.kt

@@ -0,0 +1,7 @@
+class C(val x: Short)
+
+fun box(): String {
+    val a: Short = 1
+    val b: C? = C(1)
+    return if (a.equals(b?.x)) "OK" else "fail"
+}

compiler/testData/codegen/bytecodeText/boxingOptimization/safeCallToPrimitiveEquality.kt

@@ -1,10 +1,25 @@
+// FILE: J.java
+import org.jetbrains.annotations.NotNull;
+
+public interface J {
+    @NotNull
+    public Integer foo();
+}
+
+// FILE: test.kt
 fun Long.id() = this
 
+fun Short.id() = this
+
 fun String.drop2() = if (length >= 2) subSequence(2, length) else null
 
 fun doSimple1(s: String?) = s?.length == 3
 
-fun doLongReceiver1(x: Long) = x?.id() == 3L
+fun doJava1(s: String?, j: J) = s?.length == j.foo()
+
+fun doLongReceiver1(x: Long?) = x?.id() == 3L
+
+fun doShortReceiver1(x: Short?, y: Short) = x?.id() == y
 
 fun doChain1(s: String?) = s?.drop2()?.length == 1
 
@@ -13,11 +28,16 @@ fun doIf1(s: String?) =
 
 fun doSimple2(s: String?) = 3 == s?.length
 
-fun doLongReceiver2(x: Long) = 3L == x?.id()
+fun doJava2(s: String?, j: J) = j.foo() == s?.length
+
+fun doLongReceiver2(x: Long?) = 3L == x?.id()
+
+fun doShortReceiver2(x: Short?, y: Short) = y == x?.id()
 
 fun doChain2(s: String?) = 1 == s?.drop2()?.length
 
 fun doIf2(s: String?) =
         if (1 == s?.length) "A" else "B"
 
-// 0 valueOf
+// `doJava1`/`doJava2` box `s?.length` instead of unboxing `j.foo()`:
+// 2 valueOf

compiler/testData/codegen/bytecodeText/intrinsicsCompare/byteSmartCast_after.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +ProperIeee754Comparisons
-// IGNORE_BACKEND_FIR: JVM_IR
 fun equals3(a: Byte?, b: Byte?) = a != null && b != null && a == b
 
 fun equals4(a: Byte?, b: Byte?) = if (a is Byte && b is Byte) a == b else null!!
@@ -21,10 +20,9 @@ fun less5(a: Any?, b: Any?) = if (a is Byte && b is Byte) a < b else true
 // 3 IF_ICMPGE
 
 // JVM_IR_TEMPLATES
-// 2 Intrinsics\.areEqual
+// 0 Intrinsics\.areEqual
 // 0 Intrinsics\.compare
-// 4 INVOKEVIRTUAL java/lang/Byte\.byteValue \(\)B
+// 8 INVOKEVIRTUAL java/lang/Byte\.byteValue \(\)B
 // 4 INVOKEVIRTUAL java/lang/Number\.byteValue \(\)B
 // 0 IFGE
 // 3 IF_ICMPGE
-

compiler/testData/codegen/bytecodeText/intrinsicsCompare/byteSmartCast_before.kt

@@ -1,6 +1,4 @@
 // !LANGUAGE: -ProperIeee754Comparisons
-// IGNORE_BACKEND_FIR: JVM_IR
-
 fun equals3(a: Byte?, b: Byte?) = a != null && b != null && a == b
 
 fun equals4(a: Byte?, b: Byte?) = if (a is Byte && b is Byte) a == b else null!!
@@ -21,9 +19,9 @@ fun less5(a: Any?, b: Any?) = if (a is Byte && b is Byte) a < b else true
 // 0 IF_ICMPGE
 
 // JVM_IR_TEMPLATES
-// 2 Intrinsics\.areEqual
+// 0 Intrinsics\.areEqual
 // 0 Intrinsics\.compare
-// 4 INVOKEVIRTUAL java/lang/Byte\.byteValue \(\)B
+// 8 INVOKEVIRTUAL java/lang/Byte\.byteValue \(\)B
 // 4 INVOKEVIRTUAL java/lang/Number\.byteValue \(\)B
 // 0 IFGE
-// 3 IF_ICMPGE
+// 3 IF_ICMPGE