…ompliance tests

The JSON schema reference was off-by-one, preventing IDEs from finding
the file and offering suggestions and documentation. Additionally the
name of the golden file was slightly off.

The type checker had to do extensive work in resolving the
`NodePath.get` method call for the `NodePath` that had an intersection
type of `ts.VariableDeclarator&{init:t.Expression}`. The `NodePath.get`
method is typed using a conditional type which became expensive to
compute with this intersection type. As a workaround, the original
`init` property is explicitly omitted which avoids the performance
cliff. This brings down the compile time by 15s.

…tive linker

The compilation result of components may have inserted template
functions into the constant pool, which would be inserted into the Babel
AST upon program exit. Babel will then proceed with visiting this newly
inserted subtree, but we have already cleaned up the linker instance
when exiting the program. Any call expressions within the template
functions would then fail to be processed, as a file linker would no
longer be available.

Since the inserted AST subtree is known not to contain yet more partial
declarations, it is safe to skip visiting call expressions when no
file linker is available.

…t an active linker

The metadata specification of queries allows for the boolean properties
`first`, `descendants` and `static` to be missing, but the linker did
not account for their omission.

This fix is tested in subsequent commits that implement compilation of
components, at which point this will be covered by the compliance tests.

…pilation of components

This commit is a precursor to supporting the partial compilation of
components, which leverages some of the compilation infrastructure that
is in place for directives.

…ponents

This commit adds the `i18nUseExternalIds` option to the linker options,
as the compliance tests exercise compilation results with and without
this flag enabled. We therefore need to configure the linker to take
this option into account, as otherwise the compliance test output would
not be identical.

Additionally, this commit switches away from spread syntax to set
the default options. This introduced a problem when the user-provided
options object did specify the keys, but with an undefined value. This
would have prevented the default options from being applied.

… compilation tests

The linker does not currently support outputting ES5 syntax, so any
compliance tests that request ES5 output cannot be run in partial
compilation mode. This commit marks these tests as pending.

…e in compliance tests

In production mode this flag defaults to `true`, but the compliance
tests override this to `false` unless it is provided. As such, the
linker should also adhere to this default as otherwise the compilation
output would not align with the output of the full tests.

There are still tests that exercise the value of this flag, together
with it being `undefined` to verify the behavior of the actual default
value.

This commit implements partial compilation of components, together with
linking the partial declaration into its full AOT output.

This commit does not yet enable accurate source maps into external
templates. This requires additional work to account for escape sequences
which is non-trivial. Inline templates that were represented using a
string or template literal are transplated into the partial declaration
output, so their source maps should be accurate. Note, however, that
the accuracy of source maps is not currently verified in tests; this is
also left as future work.

The golden files of partial compilation output have been updated to
reflect the generated code for components. Please note that the current
output should not yet be considered stable.