Commit c9f573463ebd7b4e46da4877802f2364f700e54a removed the file
TargetLibraryInfo.def but did not remove it from the module map.

Add VirtualOutputConfig.def to textual header.

Add llvm::cas::ObjectStore abstraction and InMemoryCAS as a in-memory
CAS object store implementation.

The ObjectStore models its objects as:
* Content: An array of bytes for the data to be stored.
* Refs: An array of references to other objects in the ObjectStore.
And each CAS Object can be idenfied with an unqine ID/Hash.

ObjectStore supports following general action:
* Expected<ID> store(Content, ArrayRef<Ref>)
* Expected<Ref> get(ID)

It also introduces following types to interact with a CAS ObjectStore:
* CASID: Hash representation for an CAS Objects with its context to help
  print/compare CASIDs.
* ObjectRef: A light-weight ref for an object in the ObjectStore. It is
  implementation defined so it can be optimized for
  read/store/references depending on the implementation.
* ObjectProxy: A proxy for the users of CAS to interact with the data
  inside CAS Object. It bundles a ObjectHandle and an ObjectStore
  instance.

Add Xtensa esp32 and esp8266 cpus. Implement target parser to recognise
Xtensa hardware features.

Follup-up to #147294, should fix the module build.

This ensures the generation of Attributes.inc when using
-DLLVM_ENABLE_MODULES=ON.

Replace RuntimeLibcalls.def with a tablegenerated version. This
is in preparation for splitting RuntimeLibcalls into two components.
For now match the existing functionality.

Add `CodeViewLanguages.def` to textual header in LLVM_DebugInfo_CodeView
to fix clang module build of LLVM.

Resolves warning when building with `LLVM_ENABLE_MODULES`

```
AArch64TargetParser.h:39:2: warning: missing submodule 'LLVM_Utils.TargetParser.AArch64FeatPriorities' [-Wincomplete-umbrella]
   39 | #include "llvm/TargetParser/AArch64FeatPriorities.inc"
      |  ^       ~~~~~~~
```

Add a new file to the module map and remove 2 missing files (migrated
from .def to .td).