Cocoa: Improve backtrace logging for <redacted> symbols

https://bugs.webkit.org/show_bug.cgi?id=258821
rdar://111700962

Reviewed by Wenson Hsieh.

* Source/WTF/wtf/PlatformHave.h:
* Source/WTF/wtf/StackTrace.h:
(WTF::StackTraceSymbolResolver::forEach const):
Enable backtrace_symbols on Cocoa, since we have it.
If a symbol comes back from dladdr as <redacted>, fall back to the
backtrace_symbols string, which includes:

- the symbol's image's name
- the image's DWARF UUID
- the symbol's address

...the combination of which can be used to make either better guesses about
the stack, or to actually symbolicate offline.

The strcmp check matches what `backtrace_symbols` itself does.

Canonical link: https://commits.webkit.org/266662@main

Source/WTF/wtf/PlatformHave.h

@@ -235,9 +235,6 @@
 
 #if OS(DARWIN) || (OS(LINUX) && defined(__GLIBC__) && !defined(__UCLIBC__) && !CPU(MIPS))
 #define HAVE_BACKTRACE 1
-#endif
-
-#if (OS(DARWIN) || OS(LINUX)) && (PLATFORM(GTK) || PLATFORM(WPE)) && defined(__GLIBC__) && !defined(__UCLIBC__) && !CPU(MIPS)
 #define HAVE_BACKTRACE_SYMBOLS 1
 #endif
 

Source/WTF/wtf/StackTrace.h

@@ -123,7 +123,7 @@ class StackTraceSymbolResolver {
             if (demangled)
                 name = demangled->demangledName() ? demangled->demangledName() : demangled->mangledName();
 #if HAVE(BACKTRACE_SYMBOLS)
-            if (!name)
+            if (!name || !strcmp(name, "<redacted>"))
                 name = symbols[i];
 #elif OS(WINDOWS)
             if (!name && DbgHelper::SymFromAddress(hProc, reinterpret_cast<DWORD64>(m_stack[i]), nullptr, symbolInfo))