This creates a "document" class with only user-facing document state (no parser internals).
- document: user-facing document state
- document::iterator: iterator (equivalent of ParsedJsonIterator)
- document::parser: parser state plus a "docked" document we parse into (equivalent of ParsedJson)
Usage:
```c++
auto doc = simdjson::document::parse(buf, len); // less efficient but simplest
```
```c++
simdjson::document::parser parser; // reusable parser
parser.allocate_capacity(len);
simdjson::document* doc = parser.parse(buf, len); // pointer to doc inside parser
doc = parser.parse(buf2, len); // reuses all buffers and overwrites doc; more efficient
```
* initial oss-fuzz friendly build
parts taken from libfmt, which I wrote and have the copyright to
* fix build error
* add script for building a corpus zip
see https://google.github.io/oss-fuzz/getting-started/new-project-guide/#seed-corpus
* fix zip command
* drop setting the C++ standard
* disable the minify fuzzer, does not pass oss-fuzz check-build test
* fix integer overflow in subnormal_power10
detected by oss-fuzz
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18714
* invoke the build like oss fuzz does
* document what the scripts are for and how to use them
* add a page about fuzzing
* add basic fuzzing using libFuzzer
* let cmake respect cflags, otherwise the fuzzer flags go unnoticed
also, integrates badly with oss-fuzz
* add new fuzzer for minification, simplify the old one
* add fuzzer for the dump example
* clang format