Gradle

ImmutableSet is faster than HashSet, for-loop is faster than

"functional" programming with Guava.

+review REVIEW-6544

We were putting the build time into the build receipt in

a different format than what we want in GradleVersion, which

is the only client of that information. Instead we now compute

the right value when we build the distribution and pass it verbatim

into GradleVersion.

The bootstrap classpath is often empty, so we optimize for that scenario

by making the field lazy.

In the coverage phase we use different Java vendors.

Therefore, we need to track the vendor if we want to use the build cache.

The caching pattern spec factory is expensive to create (due

to instantiating its caches) and we don't need it in the CLI

process if the actual build is run by the daemon.

We were incidentally permitting the shorthand notation when creating an

included build task reference. With recent changes, this no longer works

because the task requested doesn't match the task executed.

This commit removes the ability to provide a partially-matched task

name for an included build task reference.

This also fixes an integration test that accidentally relied on partial-name

matching, thus exposing the changed behaviour.

- Compose methods

- DRY

- Reduce accessibility of methods

- Replace `toPlatformLineSeparators("\n")` by `getPlatformLineSeparator()`

- Avoid excessive map instantiation by caching `execHandle.getEnvironment()`