Merge branch 'DCE' into backend

src/CMakeLists.txt

@@ -18,6 +18,10 @@ add_executable(sysyc
   # Backend.cpp
   SysYIRPrinter.cpp
   SysYIROptPre.cpp
+  SysYIRAnalyser.cpp
+  DeadCodeElimination.cpp
+  Mem2Reg.cpp
+  Reg2Mem.cpp
   RISCv64Backend.cpp
 )
 target_include_directories(sysyc PRIVATE ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/include)