eCos uSTL 1.3 port for review

[cetoni GmbH - Uwe Kindler]

Hello Sergei.

 >> When I remove ustl package and build infra tests without optimization,
 >   ^^^^^^^^^^^^^^^^^^^^^^^^^^
 > In fact libsupc++.a (= __cxa_pure_virtual) is not linked then
 >
 >> the issue leave the box. Well, I confirm the issue with i386-elf
 >> toolchain from eCosCentric on synthetic target too.
 >
 > Uwe, I "found" a dirty workaround for the issue using GCC options :-)
 >
 >     -Wl,--defsym -Wl,__cxa_pure_virtual=0
 >
 > So, my flags become
 >
 > cdl_option CYGBLD_GLOBAL_CFLAGS {
 >     user_value "-Wall -Wpointer-arith -Wstrict-prototypes -Wundef 
-Woverloaded-virtual -Wno-write-strings -g -O0 -ffunction-sections 
-fdata-sections -fno-rtti -fno-exceptions -Wl,--defsym 
-Wl,__cxa_pure_virtual=0 "
 > };
 >
 > ... and it was possible to build diag_sprintf{1,2} with added ustl.
 >
 > Well, it seems for me it can be solved more elegant. And that is not
 > ustl/snprintf issue.
 >
 > Sergei

thank you for your investigation and for your detailed error report. 
Does someone of the eCos folks know a better way to solve the 
__cxa_pure_virtual issue or should we go with Sergei's proposal

-Wl,--defsym -Wl,__cxa_pure_virtual=0

Regards, Uwe