[fidl] Compiler implementation for tables

Test: updated existing tests, implemented a table test suite for table edge cases

Change-Id: Id145d12f44544027d0d28c2288ebf5c6de39b446

[fidl] Clang format again, this time with column-limit 100 set

Change-Id: Id87234e4cc33b300445b755a738cff214a33fc0e

[fidl] Include declared names in FIDL tables.

This enables the name of a FIDL type to be formatted at runtime
using fidl_format_type_name(). Handy for debugging.

The strings are always generated today but they could be omitted
in the future, if desired.

Change-Id: I0cb0d2ab6e3c00a2a4b8f609d563c4bde2d6f98c

[fidl] Improve table generation for unions

We always need to generate a coding table for unions because we need to
validate the tag value. Also, we need to generate an entry for each
member of the union because we use the index of the member in the array
to associate the member with the tag value.

Change-Id: I49428c37e1e0bca6abae3025d902f656ffc5b62a

[fidl] Fix table generation for weak cycles

Previously, we would assume an identifier referred to an interface if we
had not encountered it yet. However, the identifier might refer to a
out-of-line struct.

Change-Id: Ide05f4e9533c3d2318c3adf69aad9e27bc588c83

[fidl] Correctly generate pointers inside structs

Change-Id: Id70e5bf1d35b0da38c40fca68dbf7a6a4b5277aa

[fidl] Always generate coding tables for structs

Structs may be used in interface messages, so for now always code them.

TO-894

Change-Id: I71359e89f91e8c4ecf302257577500313dccea90

[fidl] Record sizes in coded types

Coding tables for vectors need to know the element size for the vector.
In most cases, this size is known from the flat::Type. However, when
that type is an identifier (which has size 0), we must perform a lookup
to find the coded type for the identifier. Storing the size in the coded
type gives us the proper element size for such a vector.

TO-898 #done

Change-Id: I66213c0c910f426dd1858f24172c8f780a6c6cb2

[fidl] Always generate coding tables for interface message structs

TO-894 #done

Change-Id: Icf6b89ac1cc14db7d3089b4cfa989801aa8fd1e9

[fidl] Fix some details in the coding table generation

In particular, generate fidl_types in dependency order.

With this patch, types.fidl2's coding tables compile.

This patch also rationalizes the names of RequestHandle and
InterfaceHandle with those used in the backend.

TO-856 #done

Change-Id: I11e380856ca6968bfbcf20e5bcc03770bf424260

[fidl] Generate coding tables

Change-Id: I820faf84f6f9c564519b0f25e44452c28cf07449

[fidl] Fix up a comment in coded_ast.h

Change-Id: I46735b87b820c30eb6c363df4ece3f15d27e1486

[fidl] Reuse the existing types::Nullability

Change-Id: Ic150b7487bc70eeda469c90b73111a6d4ce4718f

[fidl] Refer to libraries as such

After some churn, we settled on 'library' for a related, self
contained group of fidl files.

Change-Id: I9bcc4b0301f16247f67716d3ed1a1b67e5a387d2

[build][fidl] Separate the fidl (host) lib from the compiler binary.

TO-732

Change-Id: I02625c25d3cac7bb7316370c47c765e1a66e9a01