Toolchain+LibC: Fix usage of crt files

We now configure the gcc spec files to use a different crt files for
static & PIE binaries.

This relieves us from the need to explicitly specify the desired crt0
file in cmake scripts.

Demos/DynamicObject/CMakeLists.txt

@@ -1,6 +1,5 @@
 set(SOURCES
     main.cpp
-    ../../Libraries/LibC/crt0_shared.cpp
 )
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -nostartfiles -lgcc_s -pie -fpic ")