According to the old certification reports at ASE Certifications on Solaris (Sparc) - SAP ASE - SCN Wiki, no OS patches were needed. Solaris 2.9 did require 12.5.3 ESD 1 and higher, so ESD 7 certainly qualifies.
The certification report for Solaris 2.10 had this note of interest "ASE 12.5.2 (64bit) or above required. Feb 2005 OS release was used for this certification. No additional patch installed. ASE 12.5.3 ESD#5 supports Sun Containers and Zones. Also tested/supported on Sun's Niagara (CoolThreads) hardware. The ZFS file system is supported. ASE cannot be supported on ZFS-raw due to an OS issue that can lead to data loss."
All somewhat moot as 12.5.3 is long since EOL, but does give a warm fuzzy feeling that it might work ok. Note that the most recent rollups of 12.5.4 (also EOL, but newer) are can be found on the SAP support portal under the "archives" section.
-bret