tree a0c3d3e9f36395e7aace9f204e22f8790c6d59cb
parent 23bfed2a10b9b228c63ce70526108ead7b5f8d67
author Jiyong Park <jiyong@google.com> 1599026421 +0900
committer Jiyong Park <jiyong@google.com> 1610674851 +0900

Guard __libc_current_sigrtmin/max with __builtin_available

The two APIs were added for the API level 21 and beyond. Currently, its
existence is tested using the null check which is done regardless of the
min sdk version of the compilation unit. (which in turn required us to
mark the API symbol weak regardless of the min sdk version.)

Now, we have a better way of testing the API availability;
__builtin_available. The null check is replaced with the call to the
compiler-provided macro which determines if the code is running in a
version of OS where the API is known to exist.

Bug: 150860940
Bug: 134795810
Test: m
Change-Id: Ib96c78f8d3cc71d7e755d1eab86051517bbbcc44