[clang] [clang] Increase VecLib bitfield size to 4 bits in CodeGenOptions.def (PR #108804)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-x86_64-debian` running on `lldb-x86_64-debian` while building `clang` at step 3 "cmake-configure".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/162/builds/6566

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 3 (cmake-configure) failure: cmake (failure)
...

  LLVM's build system enforces that all source files are added to a build
  target, that exactly one build target exists in each directory, and that
  this target lists all files in that directory.  If you want multiple
  targets in the same directory, add PARTIAL_SOURCES_INTENDED to the target
  specification, though it is discouraged.

  Please update
  /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/clang/unittests/CodeGen/CMakeLists.txt


Call Stack (most recent call first):
  cmake/modules/LLVMProcessSources.cmake:62 (llvm_check_source_file_list)
  cmake/modules/AddLLVM.cmake:997 (llvm_process_sources)
  cmake/modules/AddLLVM.cmake:1052 (generate_llvm_objects)
  cmake/modules/AddLLVM.cmake:1742 (add_llvm_executable)
  /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/clang/unittests/CMakeLists.txt:23 (add_unittest)
  /home/worker/2.0.1/lldb-x86_64-debian/llvm-project/clang/unittests/CodeGen/CMakeLists.txt:7 (add_clang_unittest)


-- Enable SWIG to generate LLDB bindings: TRUE
-- Enable editline support in LLDB: TRUE
-- Enable curses support in LLDB: TRUE
-- Could NOT find LibLZMA (missing: LIBLZMA_LIBRARY LIBLZMA_INCLUDE_DIR LIBLZMA_HAS_AUTO_DECODER LIBLZMA_HAS_EASY_ENCODER LIBLZMA_HAS_LZMA_PRESET) 
-- Enable LZMA compression support in LLDB: FALSE
-- Could NOT find Lua (missing: LUA_LIBRARIES LUA_INCLUDE_DIR) (Required is exact version "5.3")
-- Could NOT find LuaAndSwig (missing: LUA_LIBRARIES LUA_INCLUDE_DIR) 
-- Enable Lua scripting support in LLDB: FALSE
-- Found Python3: /usr/bin/python3 (found version "3.11.2") found components: Interpreter Development Development.Module Development.Embed 
-- Enable Python scripting support in LLDB: TRUE
-- Found LibXml2: /usr/lib/x86_64-linux-gnu/libxml2.so (found suitable version "2.9.14", minimum required is "2.8") 
-- Enable Libxml 2 support in LLDB: TRUE
-- Enable libfbsdvmcore support in LLDB: 0
-- LLDB version: 20.0.0git
-- Skipping FreeBSDKernel plugin due to missing libfbsdvmcore
-- Symbols (liblldb): exporting all symbols from the lldb namespace
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- Registering ExampleIRTransforms as a pass plugin (static build: OFF)
-- Registering Bye as a pass plugin (static build: OFF)
-- Failed to find LLVM FileCheck
-- Google Benchmark version: v0.0.0, normalized to 0.0.0
-- Enabling additional flags: -DINCLUDE_DIRECTORIES=/home/worker/2.0.1/lldb-x86_64-debian/llvm-project/third-party/benchmark/include
-- Performing Test HAVE_THREAD_SAFETY_ATTRIBUTES -- success
-- Performing Test HAVE_GNU_POSIX_REGEX -- failed to compile
-- Performing Test HAVE_POSIX_REGEX -- success
-- Performing Test HAVE_STEADY_CLOCK -- success
-- Performing Test HAVE_PTHREAD_AFFINITY -- success
-- Configuring incomplete, errors occurred!
See also "/home/worker/2.0.1/lldb-x86_64-debian/build/CMakeFiles/CMakeOutput.log".
See also "/home/worker/2.0.1/lldb-x86_64-debian/build/CMakeFiles/CMakeError.log".

```

</details>

https://github.com/llvm/llvm-project/pull/108804