This required dealing with a *lot* of fallout, but it's all basically
just switching from DeprecatedFlyString to either FlyString or
Optional<FlyString> in a hundred places to accommodate the change.
These are currently initialized in a [[gnu::constructor]], which has a
weird initialization order. These constructors are invoked before main()
and, incidentally, before any user-defined default constructors of the
static strings they are initializing.
This will become an issue when these strings are ported to FlyString,
which has a user-defined default constructor. In that scenario, when the
FlyString constructor is executed after the [[gnu::constructor]], the
strings will be "reset" to the empty string.
Instead of relying on a non-standard compiler extension here, let's just
initialize these strings explicitly during main-thread VM creation, as
this now happens in WebContent's main().
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *