Add LFSR tests using LFSR16 testing infrastructure. This also adds
tests that are the same as the examples shown for LFSR scaladoc.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Builds out PRNG and LFSR type hierarchy. PRNG is the base class of
LFSR of which Galois and Fibonacci are concrete implementations.

PRNGs contain state (a UInt) and an update (delta) function. They have
a compile-time optional seed to set the PRNG state. The seed/state can
also be set at run-time. PRNGs can be run-time parameterized based on
how many updates they should do per cycle and whether or not to send
the seed through step-count state updates before loading it. (h/t
@jwright6323)

LFSRs are parameterized in a reduction operation (XOR or XNOR). An
LFSR that does NOT have a seed will be automatically initialized to a
minimally safe state (set/reset one bit) based on their reduction
operation. (h/t @aswaterman)

Adds Galois and Fibonacci LFSRs that define appropriate update
functions. Companion objects provide helpers to automatically generate
maximal period variants. Taps are provide for a very large set of
widths. The LFSR companion object provides an apply method to generate
a Fibonacci LFSR random variable (like the old LFSR16).

Make LFSR testing generic to enable it to test other LFSRs.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Closes #1075.

This is necessary to support code that imports an implicit conversion
from Int to UInt

Create Chisel IR Port() in a way that Converter is happy with.
Also add more extensive test suite for future-proofing.

Close #1063

This causes sbt tasks (run, test, etc.) to fork to a separate JVM to
avoid running out of metaspace. This issue crops up for developers or
users repeatedly running sbt tasks in the same sbt session.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

- Introduce internal helper `castToInt`, which issues an error when the input
BigInt can't be represented as Int.

- Use `castToInt` wherever we were using `toInt` in a potentially unsafe way.

This is necessary to use ChiselEnum in aggregates where things are
casted using .asTypeOf

Previously, including an empty aggregate in a Bundle would cause
a MixedDirectionAggregateException because it has no elements and thus
doesn't have a direction

* Add SampleElementBinding for Vec sample elements
* Add ActualDirection.Empty for bound empty aggregates

Force clients to access 'DontCare' through the chisel3 package to ensure it's created as a chisel3 object and not a client object.

Discover a working combination of aggregate usage to enable coverage of subproject testing but publish a single Jar.
Use "scalastyle-test-config.xml" for scalastyle config in tests.
Enable "_" in method names and accept method names ending in "_=".
Re-sync scalastyle-test-config.xml with scalastyle-config.xml
This should finally fix #772.

* Turned off strong enum annotations because they weren't working with Vec
indexes
* Add new EnumVecAnnotation for vecs of enums and vecs of bundles with
enum fields
* Changed Clock's width parameter back to a fixed constant value of 1
* Fixed enum annotations for Vecs of Bundles which contain enum elements
* Fixed usage of "when/otherwise" to use consistent style

* Replace textual release version with Shields SemVer badge.

* Provide useful button action for release badge.

Co-Authored-By: Jack Koenig <jack.koenig3@gmail.com>
Co-Authored-By: Jim Lawson <ucbjrl@berkeley.edu>

* Update style warnings now that subprojects are aggregated.
Use "scalastyle-test-config.xml" for scalastyle config in tests.
Enable "_" in method names and accept method names ending in "_=".
Re-sync scalastyle-test-config.xml with scalastyle-config.xml

* Remove bogus tests that crept in with git add

* Add missing import.

Tighten inferred width for PopCount

This changes from using the chiselname annotation on Pipe.apply to
using an explicit TransitName. This results in an improved name for
created valid and bits registers.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>