For libm, use a macro for aliasing symbols.

Change-Id: Ibd42ebc387c2bf3eba9aa96091770915b4b34184
diff --git a/libm/x86/e_cosh.S b/libm/x86/e_cosh.S
index 6942028..ecea8f4 100644
--- a/libm/x86/e_cosh.S
+++ b/libm/x86/e_cosh.S
@@ -272,8 +272,7 @@
 # -- End  cosh
 
 # Start file scope ASM
-.weak coshl
-.equ coshl, cosh
+ALIAS_SYMBOL(coshl, cosh);
 # End file scope ASM
 	.section .rodata, "a"
 	.align 16