[HLSL] Use hlsl_device address space for getpointer.

We add the hlsl_device address space to represent the device memory
space as defined in section 1.7.1.3 of the [HLSL
spec](https://microsoft.github.io/hlsl-specs/specs/hlsl.pdf).

Fixes #127075

# Conflicts:
#	clang/test/CodeGenHLSL/builtins/StructuredBuffers-subscripts.hlsl

Author: s-perron

clang/include/clang/Basic/AddressSpaces.h

@@ -60,6 +60,7 @@ enum class LangAS : unsigned {
   hlsl_groupshared,
   hlsl_constant,
   hlsl_private,
+  hlsl_device,
 
   // Wasm specific address spaces.
   wasm_funcref,

clang/lib/AST/Type.cpp

@@ -94,10 +94,12 @@ bool Qualifiers::isTargetAddressSpaceSupersetOf(LangAS A, LangAS B,
          (A == LangAS::Default &&
           (B == LangAS::cuda_constant || B == LangAS::cuda_device ||
            B == LangAS::cuda_shared)) ||
-         // `this` overloading depending on address space is not ready,
-         // so this is a hack to allow generating addrspacecasts.
-         // IR legalization will be required when this address space is used.
+         // In HLSL, the this pointer for member functions points to the default
+         // address space. This causes a problem if the structure is in
+         // a different address space. We want to allow casting from these
+         // address spaces to default to work around this problem.
          (A == LangAS::Default && B == LangAS::hlsl_private) ||
+         (A == LangAS::Default && B == LangAS::hlsl_device) ||
          // Conversions from target specific address spaces may be legal
          // depending on the target information.
          Ctx.getTargetInfo().isAddressSpaceSupersetOf(A, B);

clang/lib/AST/TypePrinter.cpp

@@ -2617,6 +2617,8 @@ std::string Qualifiers::getAddrSpaceAsString(LangAS AS) {
     return "hlsl_constant";
   case LangAS::hlsl_private:
     return "hlsl_private";
+  case LangAS::hlsl_device:
+    return "hlsl_device";
   case LangAS::wasm_funcref:
     return "__funcref";
   default:

clang/lib/Basic/Targets/AArch64.h

@@ -46,6 +46,7 @@ static const unsigned ARM64AddrSpaceMap[] = {
     0, // hlsl_groupshared
     0, // hlsl_constant
     0, // hlsl_private
+    0, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref

clang/lib/Basic/Targets/AMDGPU.cpp

@@ -63,6 +63,7 @@ const LangASMap AMDGPUTargetInfo::AMDGPUDefIsGenMap = {
     // FIXME(pr/122103): hlsl_private -> PRIVATE is wrong, but at least this
     // will break loudly.
     llvm::AMDGPUAS::PRIVATE_ADDRESS, // hlsl_private
+    llvm::AMDGPUAS::GLOBAL_ADDRESS,  // hlsl_device
 };
 
 const LangASMap AMDGPUTargetInfo::AMDGPUDefIsPrivMap = {
@@ -89,6 +90,7 @@ const LangASMap AMDGPUTargetInfo::AMDGPUDefIsPrivMap = {
     llvm::AMDGPUAS::FLAT_ADDRESS,     // hlsl_groupshared
     llvm::AMDGPUAS::CONSTANT_ADDRESS, // hlsl_constant
     llvm::AMDGPUAS::PRIVATE_ADDRESS,  // hlsl_private
+    llvm::AMDGPUAS::GLOBAL_ADDRESS,   // hlsl_device
 };
 } // namespace targets
 } // namespace clang

clang/lib/Basic/Targets/DirectX.h

@@ -44,6 +44,7 @@ static const unsigned DirectXAddrSpaceMap[] = {
     3, // hlsl_groupshared
     2, // hlsl_constant
     0, // hlsl_private
+    0, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref

clang/lib/Basic/Targets/NVPTX.h

@@ -48,6 +48,7 @@ static const unsigned NVPTXAddrSpaceMap[] = {
     0, // hlsl_groupshared
     0, // hlsl_constant
     0, // hlsl_private
+    0, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref

clang/lib/Basic/Targets/SPIR.h

@@ -49,6 +49,7 @@ static const unsigned SPIRDefIsPrivMap[] = {
     0,  // hlsl_groupshared
     2,  // hlsl_constant
     10, // hlsl_private
+    11, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref
@@ -84,6 +85,7 @@ static const unsigned SPIRDefIsGenMap[] = {
     0,  // hlsl_groupshared
     0,  // hlsl_constant
     10, // hlsl_private
+    11, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref

clang/lib/Basic/Targets/SystemZ.h

@@ -44,6 +44,7 @@ static const unsigned ZOSAddressMap[] = {
     0, // hlsl_groupshared
     0, // hlsl_constant
     0, // hlsl_private
+    0, // hlsl_device
     0  // wasm_funcref
 };
 

clang/lib/Basic/Targets/TCE.h

@@ -53,6 +53,7 @@ static const unsigned TCEOpenCLAddrSpaceMap[] = {
     0, // hlsl_groupshared
     0, // hlsl_constant
     0, // hlsl_private
+    0, // hlsl_device
     // Wasm address space values for this target are dummy values,
     // as it is only enabled for Wasm targets.
     20, // wasm_funcref