Fix handling of dontcall attributes for arches that lower calls via fastSelectInstruction

Author: dpaoliello

llvm/lib/Target/ARM/ARMFastISel.cpp

@@ -2504,6 +2504,7 @@ bool ARMFastISel::SelectCall(const Instruction *I,
   // Set all unused physreg defs as dead.
   static_cast<MachineInstr *>(MIB)->setPhysRegsDeadExcept(UsedRegs, TRI);
 
+  diagnoseDontCall(*CI);
   return true;
 }
 

llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -912,6 +912,8 @@ bool WebAssemblyFastISel::selectCall(const Instruction *I) {
 
   if (!IsVoid)
     updateValueMap(Call, ResultReg);
+
+  diagnoseDontCall(*Call);
   return true;
 }