Code to periodically track IProfiler overhead

[mpirvu]

Every 5 seconds we will print the number of profiling entries, the CPU taken by the IProfiler thread and the top 5 methods that received profiling samples.
The code is not active to minimize overhead. In order to compile it in one needs to define TRACK_SAMPLE_SOURCES Also, to activate it at runtime, one needs to define the following env var: TR_TrackIProfilerActivity

[mpirvu]

jenkins compile all jdk8,jdk23

[mpirvu]

build failures on mac likely because is not included:

12:17:25  /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/utility:306:9: error: implicit instantiation of undefined template 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >'
12:17:25      _T2 second;
12:17:25          ^
12:17:25  /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/unordered_map:638:16: note: in instantiation of template class 'std::__1::pair<const J9ROMMethod *const, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >' requested here
12:17:25      value_type __cc;
12:17:25                 ^
12:17:25  /Users/jenkins/workspace/Build_JDK23_x86-64_mac_Personal/openj9/runtime/compiler/runtime/IProfiler.cpp:4187:55: note: in instantiation of template class 'std::__1::__hash_value_type<const J9ROMMethod *, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >' requested here
12:17:25        const std::string methodName = (methodEntryIter != methodNames.end()) ? methodEntryIter->second : "";

[mpirvu]

jenkins compile aix,amac jdk8,jdk23

[mpirvu]

jenkins compile zlinux jdk8

[mpirvu]

jenkins compile aix,amac,zlinux jdk8,jdk23