For libm, use a macro for aliasing symbols.

Change-Id: Ibd42ebc387c2bf3eba9aa96091770915b4b34184
diff --git a/libm/x86/s_tan.S b/libm/x86/s_tan.S
index 621c94a..3ee2107 100644
--- a/libm/x86/s_tan.S
+++ b/libm/x86/s_tan.S
@@ -284,8 +284,7 @@
 # -- End  tan
 
 # Start file scope ASM
-.weak tanl
-.equ tanl, tan
+ALIAS_SYMBOL(tanl, tan);
 # End file scope ASM
 	.section .rodata, "a"
 	.align 16