Base: Add CrashReporter(1), dbgputstr(2), dump_backtrace(2) manpages

Importantly, these document two nonstandard system
calls that Serenity provides.

Base/usr/share/man/man1/Applications/CrashReporter.md

@@ -0,0 +1,37 @@
+## Name
+
+![Icon](/res/icons/16x16/app-crash-reporter.png) CrashReporter - information about crashed programs
+
+[Open](file:///bin/CrashReporter)
+
+## Synopsis
+
+```sh
+$ CrashReporter [--unlink] <coredump-path>
+```
+
+## Description
+
+CrashReporter informs about crashed programs by providing a GUI to examine the crashed program's last state.
+
+![](CrashReporter.png)
+
+The four main tabs display the call stack (or backtrace) when the program crashed, the CPU registers just before crashing, the environment variables and the mapped memory regions. For registers and backtrace, there is one tab per thread.
+
+The buttons allow to open the relevant files in HackStudio, or to save the text of the backtrace to a file.
+
+If CrashDaemon is running, CrashReporter is automatically opened when a program crashes.
+
+## Options
+
+-   `--help`: Display help message and exit
+-   `--version`: Print version
+-   `--unlink`: Delete the coredump after it's parsed
+
+## Arguments
+
+-   `coredump-path`: Path to the core dump file to display
+
+## See Also
+
+-   [`dump_backtrace`(2)](help://man/2/dump_backtrace)

Base/usr/share/man/man1/crash.md

@@ -57,3 +57,7 @@ $ crash -F
 Testing: "Write to freed memory"
 Shell: Job 1 (crash -F) Segmentation violation
 ```
+
+## See Also
+
+-   [`dump_backtrace`(2)](help://man/2/dump_backtrace)

Base/usr/share/man/man2/dbgputstr.md

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+## Name
+
+dbgputstr - print logs to the serial console
+
+## Synopsis
+
+```**c++
+#include <stdio.h>
+
+void dbgputstr(char const* characters, size_t length);
+```
+
+## Description
+
+`dbgputstr` is Serenity's generic kernel-supported logging facility. Currently, logging submitted to `dbgputstr` is directly printed to the serial console.
+
+`dbgputstr` takes as arguments a pointer to a string to be written, and the length of that string.
+
+Users should access logging functionality via the `dbg`/`dbgln` functions, which add additional process information to the log output.
+
+## Errors
+
+The C library function does not propagate errors.
+
+The system call itself can fail with the following errors:
+
+-   `EFAULT`: Invalid or inaccessible string.
+
+No error is reported if the output cannot be written to a serial device.
+
+If the return value is positive, this indicates the actual number of characters written, in case the provided string was null-terminated before the length was reached.
+
+## See Also
+
+-   [`dump_backtrace`(2)](help://man/2/dump_backtrace)

Base/usr/share/man/man2/dump_backtrace.md

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+## Name
+
+dump_backtrace - dump the process's current kernel backtrace
+
+## Synopsis
+
+```**c++
+#include <unistd.h>
+
+void dump_backtrace();
+```
+
+## Description
+
+`dump_backtrace` prints the process's kernel backtrace to the serial console. This is most useful for information about a process crash. Note that the userspace backtrace, which in general is more useful, is not printed by this syscall, since it can be printed entirely by userspace examining its own stack.
+
+The output may look something like this:
+
+```
+254.838 [#0 crash(55:55)]: Kernel + 0x000000000052b9f4  Kernel::Process::crash(int, AK::Optional<Kernel::RegisterState const&>, bool) +0x394
+254.838 [#0 crash(55:55)]: Kernel + 0x000000000050f1d4  Kernel::handle_crash(Kernel::RegisterState const&, char const*, int, bool) +0x2ec
+254.838 [#0 crash(55:55)]: Kernel + 0x000000000059e648  illegal_instruction_asm_entry +0x30
+```
+
+## Errors
+
+This syscall does not return any errors to the user.
+
+## See Also
+
+-   [`dbgputstr`(2)](help://man/2/dbgputstr)
+-   [`crash`(2)](help://man/1/crash)
+-   [`CrashReporter(1)`](help://man/1/Applications/CrashReporter)