Avoid using a variable-sized array for a tiny allocation.

[JDevlieghere]

lldb/source/Expression/DWARFExpression.cpp

1309

Why size and not 8?

[saugustine]

lldb/source/Expression/DWARFExpression.cpp

1309

Because that preserves the semantics of the original code. The original code allocates anywhere from 1 to 8 bytes, based on size `uint8_t addr_bytes[size];`. Then reads that amount from memory (line 1303 - 1304), and then passes the size of the allocation on this line (via `sizeof(addr_bytes)`).

Always passing eight here would be wrong, because the size of the pointer could have been anywhere from 1 to 8.

Not also how line 1309 read size-bytes read into addr_bytes.

lldb/source/Expression/DWARFExpression.cpp

case DW_OP_deref_size: {
                                       /*check_sectionoffset=*/true);
 
         if (!maybe_load_addr)
           return false;
 
         addr_t load_addr = *maybe_load_addr;
 
         if (load_addr == LLDB_INVALID_ADDRESS && so_addr.IsSectionOffset()) {
-          uint8_t addr_bytes[size];
+          uint8_t addr_bytes[8];
           Status error;
 
           if (exe_ctx->GetTargetRef().ReadMemory(
                   so_addr, &addr_bytes, size, error,
                   /*force_live_memory=*/false) == size) {
             ObjectFile *objfile = module_sp->GetObjectFile();
 
             stack.back().GetScalar() = DerefSizeExtractDataHelper(
-                addr_bytes, sizeof(addr_bytes), objfile->GetByteOrder(), size);
+                addr_bytes, size, objfile->GetByteOrder(), size);
             stack.back().ClearContext();
             break;
           } else {
             if (error_ptr)
               error_ptr->SetErrorStringWithFormat(
                   "Failed to dereference pointer for for DW_OP_deref_size: "
                   "%s\n",
                   error.AsCString());