Everywhere: Core dump => Coredump

We all know what a coredump is, and it feels more natural to refer to
it as a coredump (most code already does), so let's be consistent.

Userland/Libraries/LibELF/Core.h

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <AK/Types.h>
+#include <LibC/sys/arch/i386/regs.h>
+
+namespace ELF::Core {
+
+struct [[gnu::packed]] NotesEntryHeader {
+    enum Type : u8 {
+        Null = 0, // Terminates segment
+        ProcessInfo,
+        ThreadInfo,
+        MemoryRegionInfo,
+        Metadata,
+    };
+    Type type;
+};
+
+struct [[gnu::packed]] NotesEntry {
+    NotesEntryHeader header;
+    char data[];
+};
+
+struct [[gnu::packed]] ProcessInfo {
+    NotesEntryHeader header;
+    // Information is stored as JSON blob to allow arbitrary
+    // number and length of strings/objects/arrays.
+    //
+    // Keys:
+    // - "pid" (int)
+    // - "termination_signal" (u8)
+    // - "executable_path" (String)
+    // - "arguments" (Vector<String>)
+    // - "environment" (Vector<String>)
+    char json_data[]; // Null terminated
+};
+
+struct [[gnu::packed]] ThreadInfo {
+    NotesEntryHeader header;
+    int tid;
+    PtraceRegisters regs;
+};
+
+struct [[gnu::packed]] MemoryRegionInfo {
+    NotesEntryHeader header;
+    uint64_t region_start;
+    uint64_t region_end;
+    uint16_t program_header_index;
+    char region_name[]; // Null terminated
+
+    String object_name() const
+    {
+        StringView memory_region_name { region_name };
+        if (memory_region_name.contains("Loader.so"))
+            return "Loader.so";
+        auto maybe_colon_index = memory_region_name.find(':');
+        if (!maybe_colon_index.has_value())
+            return {};
+        return memory_region_name.substring_view(0, *maybe_colon_index).to_string();
+    }
+};
+
+struct [[gnu::packed]] Metadata {
+    NotesEntryHeader header;
+    // Arbitrary metadata, set via SC_set_coredump_metadata.
+    // Limited to 16 entries and 16 KiB keys/values by the kernel.
+    //
+    // Well-known keys:
+    // - "assertion": Used by LibC's __assertion_failed() to store assertion info
+    // - "pledge_violation": Used by the Kernel's REQUIRE_PROMISE() to store pledge violation info
+    char json_data[]; // Null terminated
+};
+
+}