[clang] [HLSL] Add StructuredBuffer to external sema source (PR #106316)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-linux-test-suite` running on `ppc64le-clang-test-suite` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/95/builds/3682

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: AST/HLSL/StructuredBuffer-AST.hlsl' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/clang -cc1 -internal-isystem /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/lib/clang/20/include -nostdsysteminc -triple dxil-pc-shadermodel6.0-library -x hlsl -ast-dump -DEMPTY /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl | /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/FileCheck -check-prefix=EMPTY /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/clang -cc1 -internal-isystem /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/lib/clang/20/include -nostdsysteminc -triple dxil-pc-shadermodel6.0-library -x hlsl -ast-dump -DEMPTY /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/FileCheck -check-prefix=EMPTY /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
RUN: at line 2: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/clang -cc1 -internal-isystem /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/lib/clang/20/include -nostdsysteminc -triple dxil-pc-shadermodel6.0-library -x hlsl -ast-dump /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl | /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/FileCheck /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/bin/clang -cc1 -internal-isystem /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/build/lib/clang/20/include -nostdsysteminc -triple dxil-pc-shadermodel6.0-library -x hlsl -ast-dump /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl:33:16: error: CHECK-NEXT: expected string not found in input
// CHECK-NEXT: FieldDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> implicit h 'element_type *'
               ^
<stdin>:33:62: note: scanning from here
| | |-FinalAttr 0x100275eeab8 <<invalid sloc>> Implicit final
                                                             ^
<stdin>:34:5: note: possible intended match here
| | |-FieldDecl 0x1002760a228 <<invalid sloc>> <invalid sloc> implicit h 'element_type * [[hlsl::resource_class(UAV)]]':'element_type *'
    ^

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-test-suite/clang-ppc64le-test-suite/llvm-project/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           .
           .
           .
          28: | | | |-CopyConstructor simple trivial has_const_param needs_implicit implicit_has_const_param 
          29: | | | |-MoveConstructor exists simple trivial needs_implicit 
          30: | | | |-CopyAssignment simple trivial has_const_param needs_implicit implicit_has_const_param 
          31: | | | |-MoveAssignment exists simple trivial needs_implicit 
          32: | | | `-Destructor simple irrelevant trivial needs_implicit 
          33: | | |-FinalAttr 0x100275eeab8 <<invalid sloc>> Implicit final 
next:33'0                                                                  X error: no match found
          34: | | |-FieldDecl 0x1002760a228 <<invalid sloc>> <invalid sloc> implicit h 'element_type * [[hlsl::resource_class(UAV)]]':'element_type *' 
next:33'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
next:33'1         ?                                                                                                                                     possible intended match
          35: | | | `-HLSLResourceAttr 0x1002760a1a0 <<invalid sloc>> Implicit TypedBuffer 
next:33'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          36: | | |-CXXConstructorDecl 0x1002760a318 <<invalid sloc>> <invalid sloc> StructuredBuffer<element_type> 'void ()' inline 
next:33'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          37: | | | `-CompoundStmt 0x1002760a798 <<invalid sloc>> 
next:33'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          38: | | | `-BinaryOperator 0x1002760a778 <<invalid sloc>> 'element_type * [[hlsl::resource_class(UAV)]]':'element_type *' lvalue '=' 
next:33'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          39: | | | |-MemberExpr 0x1002760a700 <<invalid sloc>> 'element_type * [[hlsl::resource_class(UAV)]]':'element_type *' lvalue .h 0x1002760a228 
...

```

</details>

https://github.com/llvm/llvm-project/pull/106316