Did you even read the HN thread you've linked to? Everyone there clearly agreed that 4.8 was not released.
EDIT: thanks hamidr for correcting me!
EDIT: thanks hamidr for correcting me!
GCC 4.8.0 released [2013-03-22] GCC internals documentation [2013-01-23] The GCC Resource Center at IITB is providing documentation, tutorials and videos about GCC internals with support from the Government of India. ARM AArch64 support [2012-10-24] A port for AArch64, the 64-bit execution state in the ARMv8 architecture, has been contributed by ARM Ltd. IBM zEnterprise EC12 support [2012-10-10] Support for the latest release of the System z mainframe zEC12 has been added to the architecture back end. This work was contributed by Andreas Krebbel of IBM.