Move core and runtime files to a single library

Now core and runtime files are build in the same library,
libarm_compute.so and libarm_compute-static.a. Create a dummy
core library for not breaking backwards compatibility.

Update documentation on fat binaries and new high priority
library.

Fixed issue on scons when using the install_dir feature.

Change-Id: I5a8a6bbe2808243eba07fd135496995259d8702f
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5845
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/docs/user_guide/library.dox b/docs/user_guide/library.dox
index e987eac..6c7b7e9 100644
--- a/docs/user_guide/library.dox
+++ b/docs/user_guide/library.dox
@@ -555,5 +555,16 @@
 - Providing information to the caller required by the computation (e.g., memory requirements)
 - Allocation of any required auxiliary memory if it isn't given by its caller explicitly
 
+@subsection architecture_experimental_build_fat_binary Build fat binary
+
+Selecting fat_binary when building Compute Library, will create a library that contains all the supported ISA features. 
+Based on the CPU support, the appropriate kernel will be selected at runtime for execution. Currently this option is
+only supported with armv8.2-a as the base architecture.
+
+@subsection architecture_experimental_build_high_priority_operators Build high priority operators
+
+Selecting high_priority when building Compute Library, one new library will be created: libarm_compute_hp and
+will contain a selected subset of the libary operators. Currently the operators are staticly set.
+
 */
 } // namespace arm_compute