Fix missing weight due to JITted code

[jhpohovey]

previously when there was JITted code (either from e.g., Java, Lua, or from Prism emulation of x64 exe on arm64 device, the cpu time would be missing function pane, as discussed in profile-explorer/issues/31

Now, shows up as something like:

Tested on traces containing toy .EXEs with Java JIT, Lua JIT, and x64 .EXE running under emulation on an Arm64 device. The naming scheme is [JIT () ], where StartModule is the module containing the thread's entry point, and ThreadName is the OS-assigned name of the thread where unmapped samples were observed. These names reflect the host thread identity, not the names of individual JITted functions being executed.

[Copilot]

Pull request overview

This PR addresses missing CPU weight in the Functions pane when samples’ instruction pointers don’t resolve to any loaded module (common with JITted/unmapped code such as Java/Lua JIT or emulation scenarios). It introduces a synthetic module/function attribution path so those samples remain visible and navigable in the UI.

Changes:

• Add a synthetic [Unknown Module] per profiled process and attribute unresolved stack frames to per-thread synthetic functions (named [JIT <ThreadName> (<ThreadId>) <StartModule>]).
• Capture Win32StartAddr for threads from ETW so the synthetic function name can include the thread’s start module.
• Keep RawProfileData.imagesMap_ alive after event processing so synthetic images can be added post-LoadingCompleted().

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/ProfileExplorerCore/Profile/ETW/ETWProfileDataProvider.cs	Creates/uses synthetic unknown module state and attributes unresolved stack frames + PMC attribution to it.
src/ProfileExplorerCore/Profile/ETW/ETWEventProcessor.cs	Records Win32StartAddr on ProfileThread from ETW thread start events.
src/ProfileExplorerCore/Profile/Data/RawProfileModel.cs	Adds Win32StartAddr to ProfileThread protobuf model.
src/ProfileExplorerCore/Profile/Data/RawProfileData.cs	Stops clearing imagesMap_ during LoadingCompleted() to allow adding synthetic images after ETW processing.

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

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Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/ProfileExplorerCore/Profile/ETW/ETWProfileDataProvider.cs:1545

• When a PMC event maps to the synthetic unknown module, this still calls GetModuleBuilder(...), which can be relatively expensive and will always early-exit later due to missing debug info. For traces with lots of unmapped/JIT PMC samples, this becomes avoidable overhead. Consider short-circuiting when frameImage.ModuleName == "[Unknown Module]" (or frameImage == unknownModuleImage_) so only module-level counters are recorded without creating a module builder.

      if (frameImage != null) {
        profileData_.AddModuleCounter(frameImage.ModuleName, counter.CounterId, 1);
        var profileModuleBuilder = GetModuleBuilder(rawProfile, frameImage, context.ProcessId, symbolSettings);

        if (profileModuleBuilder == null) {
          continue;
        }

        if (!profileModuleBuilder.HasDebugInfo) {
          continue;
        }

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Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

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Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

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Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

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