[PSEH] Add implementation for GCC amd64

Also, put include directory next to the library and use
target_include_directories(.. INTERFACE ..) to get this right.
This is because :
 - Having includes & implementation in two different places buggers me
 - This makes sure that there is no "if it compiles everything is fine" behaviour from anyone
   because now even static libraries need it for GCC amd64 build
Also add __USE_PSEH2__ define for the non SEH-aware compilers out there and use it in a few headers
where we define macros involving __try

sdk/cmake/host-tools.cmake

@@ -35,6 +35,7 @@ function(setup_host_tools)
             -DCMAKE_INSTALL_PREFIX=${REACTOS_BINARY_DIR}/host-tools
             -DTOOLS_FOLDER=${REACTOS_BINARY_DIR}/host-tools/bin
             -DGCC_PLUGIN_DIR=${GCC_PLUGIN_DIR}
+            -DTARGET_COMPILER_ID=${CMAKE_C_COMPILER_ID}
         BUILD_ALWAYS TRUE
         INSTALL_COMMAND ${CMAKE_COMMAND} -E true
         BUILD_BYPRODUCTS ${HOST_TOOLS_OUTPUT}