and use that to fix up usused variable declarations and parameters that
are caused by transformations.
also add a transformation to replace global variable init with
`undefined`.
Now it works like this:
1. Walk the AST of the source file looking for independent
reductions and collecting them all into an array list.
2. Randomize the list of transformations. A future enhancement will add
priority weights to the sorting but for now they are completely
shuffled.
3. Apply a subset consisting of 1/2 of the transformations and check for
interestingness.
4. If not interesting, half the subset size again and check again.
5. Repeat until the subset size is 1, then march the transformation
index forward by 1 with each non-interesting attempt.
At any point if a subset of transformations succeeds in producing an interesting
result, restart the whole process, reparsing the AST and re-generating the list
of all possible transformations and shuffling it again.
As for std.zig.render, the fixups operate based on AST Node Index rather
than Nth index of the function occurence. This allows precise control
over how to mutate the input.
This reverts a change introduced in #17400 causing a bug when
decompressing an RLE block into a ring buffer.
RLE blocks contain only a single byte of data to copy into the output,
so attempting to copy a slice causes buffer overruns and incorrect
decompression.
This incremental compilation logic will need to be reworked so that it
does not depend on buried pointers - that is, long-lived pointers that
are owned by non-top-level objects such as Decl.
In the meantime, this fixes memory leaks since the memory management of
these dependencies has bitrotted.
Arrays are currently always passed by reference, this means that we
always keep the value in linear memory and never load it to Wasm's
stack. Scalar values however do get lowered to Wasm's stack.
This means when bitcasting from an array to a scalar value, we must
load the memory of the array as such scalar type. To bitcast
a scalar type to an array, we allocate a new temporary in the
linear data segment, and then store the scalar value there.
Use inline to vastly simplify the exposed API. This allows a
comptime-known endian parameter to be propogated, making extra functions
for a specific endianness completely unnecessary.