IR: cleanup expression implementations

Remove unused constructors with descriptors, minimize usages of
secondary constructors and make some properties non-lateinit, fix some
inspections.

(cherry picked from commit 98ad94e630f86bd2c92fc8e2cf0f8796de6002cc)

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -1098,7 +1098,7 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
                     }
                 }
 
-                if (catch.parameter.type == context.builtIns.throwable.defaultType) {
+                if (catch.catchParameter.descriptor.type == context.builtIns.throwable.defaultType) {
                     genCatchBlock()
                     return      // Remaining catch clauses are unreachable.
                 } else {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/FinallyBlocksLowering.kt

@@ -267,12 +267,11 @@ internal class FinallyBlocksLowering(val context: Context): FileLoweringPass, Ir
                     type              = context.irBuiltIns.nothingType,
                     tryResult         = transformedTry,
                     catches           = listOf(
-                            irCatch(catchParameter).apply {
+                            irCatch(catchParameter, irBlock {
-                                result = irBlock {
+                                +copy(finallyExpression)
-                                    +copy(finallyExpression)
+                                +irThrow(irGet(catchParameter))
-                                    +irThrow(irGet(catchParameter))
+                            })
-                                }
+                    ),
-                            }),
                     finallyExpression = null
             )
             using(TryScope(syntheticTry, transformedFinallyExpression, this)) {