BaseTools: Add GCC49 toolchain; align data sections to 0x40

BaseTools: Add GCC49 toolchain; align data sections to 0x40

GCC 4.9 may use 64-byte (0x40) alignment for data sections.

Therefore we use a different link script for GCC 4.9. The only
difference from the gcc4.4-ld-script is the alignment for data
sections.

When using the GCC48 toolchain with GCC 4.9, this error would be
encountered by GenFw:
> GenFw: ERROR 3000: Invalid
>   Unsupported section alignment.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Yingke Liu <yingke.d.liu@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15697 6f19259b-4bc3-4df7-8a09-765794883524