Code such as
```
val b = getBoolean()
if (b) 4
else if (b) 5
```
didn't generate a value on the stack always and therefore would
have control-flow paths leading to a pop instruction with nothing
on the stack.
Change-Id: I09d059f361e56a41880006e3f4e51e9acdbd167d
Initializers are "set field" expressions and are considered redundant
when they are:
1. In the primary constructor; and
2. Set the field to `0`, `false`, or `null`; and
3. Have a `null` origin. I.e., not in an initializer block or
constructor body, and therefore the field could not have been set by a
prior expression.
Simplify MultifileClassPartCodegen, remove related tests and change some
tests to use const val instead of val because backing fields for const
properties are stored in the facade, not parts
#KT-23701 Fixed
Simplify ifs when branches have condition true/false.
Simplify blocks containing only a variable declaration
and a variable get of the same variable. Simplify to
just the condition.
Do not introduce temporary variables for constants for
null checks. Constants have no side-effects and can be
reloaded freely instead of going through a local.
This simplifies code such as "42.toLong()!!" so that the
resulting code has no branches and uses no locals. The
simplifications happen as follows:
```
block
temp = 42.toLong()
when
(temp == null) throw NPE
(true) load temp
---> null test simplification
block
temp = 42.toLong()
when
(false) throw NPE
(true) load temp
---> when simplification
block
temp = 42.toLong()
load temp
---> block simplification
42.toLong()
```
* if enum class has abstract members, then it is ABSTRACT
* otherwise, if enum class has entries with members, then it is OPEN
* otherwise, it is FINAL.
In case of the same class defined in different modules they contain
different descriptors instances in their scope that might lead
to failing assertion in findConcreteSuperDeclaration
because there are overridden from different modules
It might happen even in the compiler because of different built-in modules
defined for sources-module and for dependencies' one
^KT-29320 Fixed
In super class constructor arguments, 'this' can be resolved
as a reference to a companion object of a superclass.
This breaks an assumption in psi2ir that 'this' can only refer to some
receiver from the current scope.
If 'this' refers to an 'object' (including 'companion obejct'),
and we are not inside the corresponding class scope,
then 'this' represents a reference to a singleton instance "by name"
(represented as IrGetObjectValue).
Introduce lowering to remove null checks for primitive type
expressions and replace them with true/false. Side-effects
are preserved.
Generate ifnull/ifnonnull instructions for null checks instead
of materializing a null literal for an equality check.
Dmitry Petrov