[sgen] Fix overflow occurring with large object allocations.  Fixes #17590.
[sgen] Hint OOM exception branch as not taken.
[sgen] new T[-1] must throw OverflowException, not OOM.

Fixes failure in mini/arrays.cs.
[runtime] Remove overly pessimistic test.

The test asserts that we can't allocate int arrays with 2G elements.
With SGen on 64 bits, however, we can, which is a feature, not
a bug.
[system.xml] Support more primitive types in XmlReader::ReadContentAs
[arm] Use d0/d1 as fp scratch regs on non-hard float platforms. Hopefully fixes #17597.
[system.xml] Add more invalid argument checks
[system] Updates to WebUtility decoders and encoders
[NTLM]: Add new 'NtmlSettings' class to hold the 'DefaultAuthLevel' property.

When the NTLM sources are compiled into System.dll, then we need to store the
configuration variables there and peek/poke it in Mono.Security.
[mcs] Don't report any not applicable operator errors during constant folding.
Added Linux travis branch