[AArch64] Make -mcpu, -march and -mtune case-insensitive.

gcc/

	* config/aarch64/aarch64.opt
	(mcpu, march, mtune): Make case-insensitive.

From-SVN: r206797

gcc/ChangeLog

+2014-01-20  Alan Lawrence  <alan.lawrence@arm.com>
+
+	* config/aarch64/aarch64.opt
+	(mcpu, march, mtune): Make case-insensitive.
+
 2014-01-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/59880

gcc/config/aarch64/aarch64.opt

@@ -88,15 +88,15 @@ Target RejectNegative Joined Enum(tls_type) Var(aarch64_tls_dialect) Init(TLS_DE
 Specify TLS dialect
 
 march=
-Target RejectNegative Joined Var(aarch64_arch_string)
+Target RejectNegative ToLower Joined Var(aarch64_arch_string)
 -march=ARCH	Use features of architecture ARCH
 
 mcpu=
-Target RejectNegative Joined Var(aarch64_cpu_string)
+Target RejectNegative ToLower Joined Var(aarch64_cpu_string)
 -mcpu=CPU	Use features of and optimize for CPU
 
 mtune=
-Target RejectNegative Joined Var(aarch64_tune_string)
+Target RejectNegative ToLower Joined Var(aarch64_tune_string)
 -mtune=CPU	Optimize for CPU
 
 mabi=