[clang] [HLSL] Make it possible to assign an array from a cbuffer (PR #134174)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `premerge-monolithic-linux` running on `premerge-linux-1` while building `clang` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/29445

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

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: CodeGenHLSL/ArrayAssignable.hlsl' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
/build/buildbot/premerge-monolithic-linux/build/bin/clang -cc1 -internal-isystem /build/buildbot/premerge-monolithic-linux/build/lib/clang/21/include -nostdsysteminc -triple dxil-pc-shadermodel6.3-library -finclude-default-header -emit-llvm -disable-llvm-passes -o - /build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl | /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl # RUN: at line 1
+ /build/buildbot/premerge-monolithic-linux/build/bin/clang -cc1 -internal-isystem /build/buildbot/premerge-monolithic-linux/build/lib/clang/21/include -nostdsysteminc -triple dxil-pc-shadermodel6.3-library -finclude-default-header -emit-llvm -disable-llvm-passes -o - /build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
+ /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl
/build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl:15:9: error: resource has implicit register binding [-Whlsl-implicit-binding]
   15 | cbuffer CBArrays {
      |         ^
1 error generated.
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/clang/test/CodeGenHLSL/ArrayAssignable.hlsl

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/134174