Rather than allocating Decl objects with an Allocator, we instead allocate
them with a SegmentedList. This provides four advantages:
* Stable memory so that one thread can access a Decl object while another
thread allocates additional Decl objects from this list.
* It allows us to use u32 indexes to reference Decl objects rather than
pointers, saving memory in Type, Value, and dependency sets.
* Using integers to reference Decl objects rather than pointers makes
serialization trivial.
* It provides a unique integer to be used for anonymous symbol names,
avoiding multi-threaded contention on an atomic counter.
* Remove the Allocator field; instead it must be passed in as a
parameter to any function that needs it.
* Rename `push` to `append` and `pushMany` to `appendSlice` to match
the conventions set by ArrayList.
I spent a long time working on this data structure, and I still think
it's a neat idea, but it has no business being in the std lib.
I'm aware of the few remaining references to SegmentedList that exist in
the std lib, but they are dead code, and so I'm leaving the dead
references as a clue that the code is dead. Cleaning up dead code will
be a separate effort that involves code coverage tools to make sure we
find it all.
std-lib-orphanage commit: 2c36a7894c689ecbaf63d5f489bb0c68773410c4
closes#7190
This change was mostly made with `zig fmt` and this also modified some whitespace. Note that in some files, `zig fmt` produced incorrect code, so the change was made manually.
* Implements #3768. This is a sweeping breaking change that requires
many (trivial) edits to Zig source code. Array values no longer
coerced to slices; however one may use `&` to obtain a reference to
an array value, which may then be coerced to a slice.
* Adds `IrInstruction::dump`, for debugging purposes. It's useful to
call to inspect the instruction when debugging Zig IR.
* Fixes bugs with result location semantics. See the new behavior test
cases, and compile error test cases.
* Fixes bugs with `@typeInfo` not properly resolving const values.
* Behavior tests are passing but std lib tests are not yet. There
is more work to do before merging this branch.
