Profiler/GPUViz: Stop allocating memory

These parsing strings are tiny, less than 64 bytes all the time. Just
stack allocate the buffer. Makes it safer to use during extenuating
circumstances as well, like SIGBUS and SIGSEGV.

FEXCore/Source/Utils/Profiler.cpp

@@ -98,15 +98,19 @@ void Shutdown() {
 void TraceObject(std::string_view const Format, uint64_t Duration) {
   if (TraceFD != -1) {
     // Print the duration as something that began negative duration ago
-    fextl::string Event = fextl::fmt::format("{} (lduration=-{})\n", Format, Duration);
-    write(TraceFD, Event.c_str(), Event.size());
+    const auto StringSize = Format.size() + strlen(" (lduration=-)\n") + 22;
+    auto Event = reinterpret_cast<char*>(alloca(StringSize));
+    auto Res = ::fmt::format_to_n(Event, StringSize, "{} (lduration=-{})\n", Format, Duration);
+    write(TraceFD, Event, Res.size);
   }
 }
 
 void TraceObject(std::string_view const Format) {
   if (TraceFD != -1) {
-    fextl::string Event = fextl::fmt::format("{}\n", Format);
-    write(TraceFD, Event.data(), Event.size());
+    const auto StringSize = Format.size() + 1;
+    auto Event = reinterpret_cast<char*>(alloca(StringSize));
+    auto Res = ::fmt::format_to_n(Event, StringSize, "{}\n", Format);
+    write(TraceFD, Event, Res.size);
   }
 }
 } // namespace GPUVis