[trace-provider] Add trace_provider_create_with_name

And deprecate the old RegisterTraceProvider fidl method.

Tested: trace record trace --help
And observe ktrace_provider's name mentioned in trace manager output.

DX-422 #comment patch

Change-Id: I7366a800d0323a62f9e820a895ab95b5d0eb159e

[fidl] Requiring fidl library dependencies to be declared with using.

A `Library` may only use dependent libraries declared with `using name;` or
`using name as alias;`. During conversion from raw to flat AST, dependencies
are registered under their full qualified name, and alias if present, such
that access can later be more directly controlled. Also checking for duplicate
imports, and giving hints when encountering missing dependencies.

Some improvements around error messaging when encountering unexpected tokens.

Test: unit tested, fx full-build, on x86 and arm, also checking vendor

This reverts commit a252133fefe6dfc9984646e737e4a616222ff678. (It is the
revert of the revert, i.e. the initial change which is
https://fuchsia.googlesource.com/zircon/+/1100bd7e89caa04defae2b54cc833c729cb3c6db)

Change-Id: Ia5c0df9d9262d130bd933fa6d889e97d809b450b

[fidl] Revert "Requiring fidl library dependencies to be declared with using."

This reverts commit 1100bd7e89caa04defae2b54cc833c729cb3c6db.

Test: git revert
Change-Id: I0d679ef1d1c97e8bf29335177356e2018899fff9

[fidl] Requiring fidl library dependencies to be declared with using.

A `Library` may only use dependent libraries declared with `using name;` or
`using name as alias;`. During conversion from raw to flat AST, dependencies
are registered under their full qualified name, and alias if present, such
that access can later be more directly controlled. Also checking for duplicate
imports, and giving hints when encountering missing dependencies.

Some improvements around error messaging when encountering unexpected tokens.

Test: unit tested, and ran on many fidl files
Change-Id: I10c5ccfc2a4215240640507cf4a8d078f671d441

[trace-provider] Add RegisterTraceProviderSynchronously

... and the ability to wait for tracing to start.
This allows programs like benchmarks to avoid having early trace
records dropped due to the benchmark starting to run before TraceManager
has sent the Start request.

DX-164 #comment patch

Tested:
trace record /pkgfs/packages/trace_stress/0/bin/trace_stress

Change-Id: I4c8e9e4cd37587e2624879fcc23720f525349238

[tracing] Add support for circular and streaming modes

Tested:
/boot/test/sys/trace-test
trace-benchmark
Further testing done on the garnet side.

Change-Id: I8ec21ba0adc57d090bbfe4be6d56fc695aa645d4

[tracing] Add beginnings of trace buffering mode support

This patch just adds the basic infrastructure.
Support for circular and streaming modes comes later.

Tested:
/system/test/sys/trace-test
trace record --buffering-mode=oneshot \
--categories=stress:example,stress:something \
/system/bin/trace-stress --count=5000
trace record --buffering-mode=circular \
--categories=stress:example,stress:something \
/system/bin/trace-stress --count=5000
[trace will be empty, but should run]
trace record --buffering-mode=streaming \
--categories=stress:example,stress:something \
/system/bin/trace-stress --count=5000
[trace will be empty, but should run]

Change-Id: I1fc28668dee652c88df9d5e669c8b4ac978604bc

[tracing] Use a fifo instead of an eventpair for TraceManager signalling

This is in preparation for bidirectional comms between TraceManager
and TraceProvider to implement double buffering.

Tested: [requires corresponding garnet patches]
trace record --duration=10 --buffer-size=1 \
--categories=stress:example,stress:something \
/system/bin/trace-stress --count=5000 --duration=10
And verify the buffer-overflow warning is seen:
WARNING ... Record got dropped ...
trace record --duration=10 --buffer-size=1 \
--categories=stress:example,stress:something \
/system/bin/trace-stress --count=5000 --duration=2
And verify TraceManager responds to prematurely closed fifo.

Change-Id: I05ae748569f233f1da77f9013453058b4904ef91

[fidl] Rename FIDL directories

These names more closely match what we publish in the SDK. Ideally, we'd
use . as the separator, but Zircon's build system cannot handle . in
directory names, so we use - instead.

Test: Builds.
Change-Id: Ia420a364d2accac39faebade8f3f8ed72088556a