Several tests got the buffer size wrong when sizeof(char_t)>1, and one
test didn't meet the carefully tuned allocation criteria under compact
mode due to the hash table usage and had to be changed a bit.

Apparently at some point OSX behavior when reading /dev/tty switched
from "can't open the file" to "the file can be opened and 0 bytes can be
read from it" which generates a wrong error and doesn't exercise the
code path we care about.

This helps make sure our error handling logic works and is exercised.

This warning is new as of GCC 7 and highlights undefined behavior in the
preprocessor that ASAN detection was relying on.

These tests currently fail for compact mode because of ->reserve()
failing.

We now check that appending a child to a moved document performs no
allocations - this is already the case, but if we neglected to copy the
allocator state this test would fail.

Large test wasn't testing shared parent condition properly - add one
more level of hierarchy so that it works as expected.

Add a test that checks that static buffer pointer was moved correctly
by checking if offset_debug still works.

Make sure we have coverage for empty documents and for large documents
that trigger compact_shared_parent != root for some pages.

Verify that move doesn't allocate and that it preserves structures
required for tree memory management and append_buffer in tact.

These just verify that move ctor/assignment operator work as expected in
simple cases - there are a number of ways in which the internal
structure can be incorrect...

These new tests test that tellg() can fail when being called the second
time, which leads to seekable implementation failing.

These tests simulate various error conditions when reading data from
streams - seeks failing in seekable streams, underflow throwing an
exception causing read to set badbit, etc.

This change also adjusts memory thresholds to cause a reliable out of
memory during construction of a final buffer for non-seekable streams.

This fixes missing coverage in translate_table_generate and
xpath_node_set_raw::append.

Hiding using namespace in common.hpp is somewhat surprising so remove
common.hpp and move using namespace into all .cpp files that need it.

Most tests have `using namespace pugi` which makes explicit
qualifications unnecessary.

These functions were deprecated via comments in 1.5 but never got the
deprecated attribute; now is the time!

Using deprecated functions produces a warning; to silence it, this
change moves the relevant tests to a separate translation unit that has
deprecation disabled.

This requires moving the list of VS versions out of
autotest-appveyor.ps1 and into appveyor.yml.

Add memory allocation failure test for concact with a very large list
and make sure we have every single axis covered with and without a
predicate, with and without a previous step.

Apparently only narrow character streams had out of memory coverage -
fix that and also split this into a separate test.

Cover both char and wchar_t stream loading in a single run instead of
using pugi::char_t.

Cover more failure cases and simplify the streambuf implementation a
bit.

Rename partition to partition3 to resolve conflicts with std::partition.

Add more memory allocation failure tests.

Adjust the buffer size to be right on the edge of the overflow, make
sure we actually output " instead of ".

This test triggers flush() condition for each optimized write() method.

New tests try to load a folder as an XML document, and a device. Both
are intended to exercise some otherwise non-hittable error paths in
load_file implementation.

This adds tests that complete branch coverage in compact pointer
encoding/decoding code (previously first_attribute was always encoded
using compact encoding in the entire test suite).

Now the only thing fuzz_setup.sh does is installing new clang; if system
clang supports -fsanitize-coverage then fuzz_setup.sh is not required.

The script only worked if clang folder was already created.

This triggers a runtime error under integer sanitizer

This was triggering an buffer read overflow with asan.

Make the file executable, fix Windows newlines and fix clang setup.

Hopefully this will allow for better fuzzing coverage

Only fuzz the parser for now.

This downloads a clang build that has support for instrumentation, and also
downloads and compiles libFuzzer.a.