The trailing 'L' was missing in the expectation.
The test got failed again. I got the following output:
ubuntu@jetson8:~$ ./t.tmp.exe Testing 29715 symbols. 1ILeeeEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE -> <-0x1.cecececececececececececececep+11983L Got instead: <-0x1.cecececececececececececececep+11983L> t.tmp.exe: C:/buildbot/temp/llvm-project/libcxxabi/test/test_demangle.pass.cpp:30001: void testFPLiterals(): Assertion `false' failed. Aborted (core dumped)
looks like it does not expect trailing >.