Add posix_get_symbol to QuRT OS.
Add posix_get_symbol to QuRT OS.


Former-commit-id: dfc0485e1a415135b83b18446f24ead188800ef0
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide