llvm-project

671e287b - [lldb] Enable chaining multiple scripted frame providers per thread (#172849)

[lldb] Enable chaining multiple scripted frame providers per thread (#172849) This patch allows threads to have multiple SyntheticFrameProviderSP instances that chain together sequentially. Each provider receives the output of the previous provider as input, creating a transformation pipeline. It changes `Thread::m_frame_provider_sp` to a vector, adds provider parameter to SyntheticStackFrameList to avoid calling back into `Thread::GetFrameProvider()` during frame fetching, updated `LoadScriptedFrameProvider()` to chain providers by wrapping each previous provider's output in a `SyntheticStackFrameList` for the next provider and finally, loads ALL matching providers in priority order instead of just the first one. The chaining works as follows: ``` Real Unwinder Frames ↓ Provider 1 (priority 10) → adds/transforms frames ↓ Provider 2 (priority 20) → transforms Provider 1's output ↓ Provider 3 (priority 30) → transforms Provider 2's output ↓ Final frame list shown to user ``` This patch also adds a test for this (test_chained_frame_providers) to verify that 3 providers chain correctly: `AddFooFrameProvider`, `AddBarFrameProvider`, `AddBazFrameProvider`. Signed-off-by: Med Ismail Bennani <ismail@bennani.ma> (cherry picked from commit 17b01bbc67c484068e174d9e9a80089102bea0e8)