This patch is to fix a regression issue that build fails
if multiple build targets given.
Two changes cause this regression issue.
One is AutoGen object __hash__ function only
hash file path and arch, missing ToolChain and build target.
The other is changing the multiple-thread-genfds function as default
build behavior. To generate the genffs command to Makefile, there
is a global data set is used, GenFdsGlobalVariable, which cause build
tool use the data of first build-target build in
the second build-target build.
Signed-off-by: Bob Feng <bob.c.feng@intel.com> Cc: Liming Gao <liming.gao@intel.com> Cc: Steven Shi <steven.shi@intel.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Liming Gao <liming.gao@intel.com>