* Use pointers instead of copying around ast.Node
Node is a 56B struct that is constantly in the hot path. Passing nodes
around by copy had a cost that started to add up. This change replaces
them by pointers. Using unsafe pointer arithmetic and converting
sibling/child indexes to relative offsets, it removes the need to carry
around a pointer to the root of the tree. This saves 8B per Node. This
space will be used to store an extra []byte slice to provide contextual
error handling on all nodes, including the ones whose data is different
than the raw input (for example: strings with escaped characters), while
staying under the size of a cache line.
* Remove conditional
* Add Raw to track range in data for parsed values
* Simplify reference tracking
* Benchmark script
* Rewrite unmarshaler using the stack
Instead of tracking the build chain using `target`s, use the stack
instead.
Working and most benchmarks look good, but regression on structs unmarshalling.
~60% slower on ReferenceFile/struct.
* Shortcut to check if last node of iterator
* Remove unecessary pointer allocation
* Skip over unused keys without marking them as seen
* Add some tests
* Fix mktemp on macos
Thomas Pelletier