Fix an issue with casting types in debig-info extension implementation

Author: VyacheslavLevytskyy

llvm/lib/Target/SPIRV/SPIRVEmitNonSemanticDI.cpp

@@ -158,9 +158,9 @@ bool SPIRVEmitNonSemanticDI::emitGlobalDI(MachineFunction &MF) {
                 // pointed on from other DI types
                 // DerivedType->getBaseType is null when pointer
                 // is representing a void type
-                if (DerivedType->getBaseType())
-                  BasicTypes.insert(
-                      cast<DIBasicType>(DerivedType->getBaseType()));
+                if (auto *BT = dyn_cast_or_null<DIBasicType>(
+                        DerivedType->getBaseType()))
+                  BasicTypes.insert(BT);
               }
             }
           }

llvm/test/CodeGen/SPIRV/debug-info/debug-type-pointer.ll

@@ -81,6 +81,8 @@
 
 ; CHECK-OPTION-NOT: DebugTypePointer
 
+%struct_wrapper = type { i32 }
+
 @gi0 = dso_local addrspace(1) global ptr addrspace(4) null, align 4, !dbg !0
 @gv0 = dso_local addrspace(1) global ptr addrspace(4) null, align 4, !dbg !5
 
@@ -278,3 +280,4 @@ define spir_func i32 @test1() !dbg !72 {
 !98 = !DILocalVariable(name: "arr1", scope: !72, file: !3, line: 35, type: !67)
 !99 = !DILocation(line: 35, column: 7, scope: !72)
 !100 = !DILocation(line: 36, column: 3, scope: !72)
+!101 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !67, size: 32, dwarfAddressSpace: 4)