Add Rust's personality function to the list of known personality functions

[majnemer]

LGTM

[mehdi_amini]

No test?

include/llvm/Analysis/EHPersonalities.h

enum class EHPersonality {
   Unknown,
   GNU_Ada,
   GNU_C,
   GNU_CXX,
   GNU_ObjC,
   MSVC_X86SEH,
   MSVC_Win64SEH,
   MSVC_CXX,
-  CoreCLR
+  CoreCLR,
+  Rust
 };
 
 /// \brief See if the given exception handling personality function is one
 /// that we understand.  If so, return a description of it; otherwise return
 /// Unknown.
 EHPersonality classifyEHPersonality(const Value *Pers);
 
 /// \brief Returns true if this personality function catches asynchronous

lib/Analysis/EHPersonalities.cpp

return StringSwitch<EHPersonality>(F->getName())
     .Case("__gxx_personality_v0",  EHPersonality::GNU_CXX)
     .Case("__gcc_personality_v0",  EHPersonality::GNU_C)
     .Case("__objc_personality_v0", EHPersonality::GNU_ObjC)
     .Case("_except_handler3",      EHPersonality::MSVC_X86SEH)
     .Case("_except_handler4",      EHPersonality::MSVC_X86SEH)
     .Case("__C_specific_handler",  EHPersonality::MSVC_Win64SEH)
     .Case("__CxxFrameHandler3",    EHPersonality::MSVC_CXX)
     .Case("ProcessCLRException",   EHPersonality::CoreCLR)
+    .Case("rust_eh_personality",   EHPersonality::Rust)
     .Default(EHPersonality::Unknown);
 }
 
 bool llvm::canSimplifyInvokeNoUnwind(const Function *F) {
   EHPersonality Personality = classifyEHPersonality(F->getPersonalityFn());
   // We can't simplify any invokes to nounwind functions if the personality
   // function wants to catch asynch exceptions.  The nounwind attribute only
   // implies that the function does not throw synchronous exceptions.