Kernel+AK: Move UBSanitizer to AK, and to AK namespace

In preparation for copying UBSanitizer to userspace, move the header to
AK :^)

AK/UBSanitizer.h

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+namespace AK::UBSanitizer {
+
+extern bool g_ubsan_is_deadly;
+
+typedef void* ValueHandle;
+
+class SourceLocation {
+public:
+    const char* filename() const { return m_filename; }
+    u32 line() const { return m_line; }
+    u32 column() const { return m_column; }
+
+private:
+    const char* m_filename;
+    u32 m_line;
+    u32 m_column;
+};
+
+enum TypeKind : u16 {
+    Integer = 0,
+    Float = 1,
+    Unknown = 0xffff,
+};
+
+class TypeDescriptor {
+public:
+    const char* name() const { return m_name; }
+    TypeKind kind() const { return (TypeKind)m_kind; }
+    bool is_integer() const { return kind() == TypeKind::Integer; }
+    bool is_signed() const { return m_info & 1; }
+    bool is_unsigned() const { return !is_signed(); }
+    size_t bit_width() const { return 1 << (m_info >> 1); }
+
+private:
+    u16 m_kind;
+    u16 m_info;
+    char m_name[1];
+};
+
+struct InvalidValueData {
+    SourceLocation location;
+    const TypeDescriptor& type;
+};
+
+struct NonnullArgData {
+    SourceLocation location;
+    SourceLocation attribute_location;
+    int argument_index;
+};
+
+struct NonnullReturnData {
+    SourceLocation attribute_location;
+};
+
+struct OverflowData {
+    SourceLocation location;
+    const TypeDescriptor& type;
+};
+
+struct VLABoundData {
+    SourceLocation location;
+    const TypeDescriptor& type;
+};
+
+struct ShiftOutOfBoundsData {
+    SourceLocation location;
+    const TypeDescriptor& lhs_type;
+    const TypeDescriptor& rhs_type;
+};
+
+struct OutOfBoundsData {
+    SourceLocation location;
+    const TypeDescriptor& array_type;
+    const TypeDescriptor& index_type;
+};
+
+struct TypeMismatchData {
+    SourceLocation location;
+    const TypeDescriptor& type;
+    u8 log_alignment;
+    u8 type_check_kind;
+};
+
+struct AlignmentAssumptionData {
+    SourceLocation location;
+    SourceLocation assumption_location;
+    const TypeDescriptor& type;
+};
+
+struct UnreachableData {
+    SourceLocation location;
+};
+
+struct ImplicitConversionData {
+    SourceLocation location;
+    const TypeDescriptor& from_type;
+    const TypeDescriptor& to_type;
+    /* ImplicitConversionCheckKind */ unsigned char kind;
+};
+
+struct InvalidBuiltinData {
+    SourceLocation location;
+    unsigned char kind;
+};
+
+struct PointerOverflowData {
+    SourceLocation location;
+};
+
+}