[codegen][debug] fix of KT-20207 (problem with accessing structs)

- removed artifacts of dwarf type generation, instead debugger will use runtime debugger functions
- fixed variable offset calculation

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt

@@ -504,14 +504,13 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
                 call(context.llvm.enterFrameFunction, listOf(slots, Int32(slotCount).llvm))
             }
             addPhiIncoming(slotsPhi!!, prologueBb to slots)
-            val slotOffset = pointerSize * slotCount
             memScoped {
                 slotToVariableLocation.forEach { slot, variable ->
-                    val expr = longArrayOf(DwarfOp.DW_OP_minus.value,
+                    val expr = longArrayOf(DwarfOp.DW_OP_plus.value,
-                            slotOffset + runtime.pointerSize * slot.toLong()).toCValues()
+                            runtime.pointerSize * slot.toLong()).toCValues()
                     DIInsertDeclaration(
                             builder       = codegen.context.debugInfo.builder,
-                            value         = slotsPhi,
+                            value         = slots,
                             localVariable = variable.localVariable,
                             location      = variable.location,
                             bb            = prologueBb,

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/DebugUtils.kt

@@ -225,20 +225,11 @@ internal fun alignTo(value:Long, align:Long):Long = (value + align - 1) / align
 internal fun  FunctionDescriptor.subroutineType(context: Context, llvmTargetData: LLVMTargetDataRef): DISubroutineTypeRef {
     return memScoped {
         DICreateSubroutineType(context.debugInfo.builder, allocArrayOf(
-                this@subroutineType.types.map { it.referenceOrValue(context, llvmTargetData) }),
+                this@subroutineType.types.map { it.diType(context, llvmTargetData) }),
                 this@subroutineType.types.size)!!
     }
 }
 
-@Suppress("UNCHECKED_CAST")
-private fun KotlinType.referenceOrValue(context: Context, llvmTargetData: LLVMTargetDataRef):DITypeOpaqueRef {
-    val refType = this.dwarfType(context, llvmTargetData)
-    return if (KotlinBuiltIns.isPrimitiveType(this))
-        refType
-    else
-        dwarfPointerType(context, refType)
-}
-
 @Suppress("UNCHECKED_CAST")
 private fun dwarfPointerType(context: Context, type: DITypeOpaqueRef) =
         DICreatePointerType(context.debugInfo.builder, type) as DITypeOpaqueRef

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -639,10 +639,8 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
             return
         }
         using(ClassScope(declaration)) {
-            debugClassDeclaration(declaration) {
+            declaration.declarations.forEach {
-                declaration.declarations.forEach {
+                it.acceptVoid(this)
-                    it.acceptVoid(this)
-                }
             }
         }
     }
@@ -1690,31 +1688,6 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
     //-------------------------------------------------------------------------//
     private fun IrElement.endColumn() = file().fileEntry.column(this.endOffset)
 
-    //-------------------------------------------------------------------------//
-    @Suppress("UNCHECKED_CAST")
-    private fun debugClassDeclaration(declaration: IrClass, body: () -> Unit): Unit {
-        val doDebugInfo = context.shouldContainDebugInfo() && declaration.descriptor.isExported()
-        val classScope = currentCodeContext.classScope() as ClassScope
-        if (doDebugInfo) context.debugInfo.types[declaration.descriptor.defaultType] = classScope.scope!!
-        body()
-        memScoped {
-            if (doDebugInfo) context.debugInfo.types[declaration.descriptor.defaultType] = DICreateStructType(
-                    refBuilder = context.debugInfo.builder,
-                    scope = context.debugInfo.compilationModule as DIScopeOpaqueRef,
-                    name = declaration.descriptor.typeInfoSymbolName,
-                    file = file().file(),
-                    lineNumber = declaration.startLine(),
-                    sizeInBits = 64 /* TODO */,
-                    alignInBits = 4 /* TODO */,
-                    derivedFrom = null,
-                    elements = classScope.members.toCValues(),
-                    elementsCount = classScope.members.size.toLong(),
-                    refPlace = context.debugInfo.types[declaration.descriptor.defaultType] as DICompositeTypeRef,
-                    flags = 0
-            ) as DITypeOpaqueRef
-        }
-    }
-
     //-------------------------------------------------------------------------//
     private fun debugFieldDeclaration(expression: IrField) {
         val scope = currentCodeContext.classScope() as? ClassScope ?: return