build: If IPO is set to "auto" turn it off when building in debug mode

Turning IPO on when debugging avoids the debugger from identifying
some of the source code.

Author: MohamedEldafrawy

CMakeLists.txt

@@ -87,7 +87,7 @@ if (VTR_IPO_BUILD STREQUAL "on")
         message(ERROR "Building with IPO unsupported with this compiler!")
     endif()
 elseif(VTR_IPO_BUILD STREQUAL "auto")
-    if (IPO_SUPPORTED)
+    if (IPO_SUPPORTED AND NOT CMAKE_BUILD_TYPE STREQUAL "debug")
         message(STATUS "Building with IPO: on (auto)")
         set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
     else()