Add a requires line to test.

Author: adrian-prantl

lldb/test/Shell/SymbolFile/absolute-symbol.s

@@ -1,4 +1,5 @@
-# RUN: %clang %s -g -c -o %t.o
+# REQUIRES: system-darwin
+# RUN: %clang %s -c -o %t.o
 # RUN: %lldb -b -o 'target modules lookup -s absolute_symbol' %t.o | FileCheck %s
 # CHECK: 1 symbols match 'absolute_symbol'
 # CHECK:   Address: 0x0000000012345678 (0x0000000012345678)