[ARC] Allow EX instruction unconditionally

gcc/
2017-05-02  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (atomic_exchangesi): EX instruction is default
	for ARC700 and ARCv2.

From-SVN: r261539

gcc/ChangeLog

+2018-06-12  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* config/arc/arc.c (atomic_exchangesi): EX instruction is default
+	for ARC700 and ARCv2.
+
 2018-06-13  Chenghua Xu <paul.hua.gm@gmail.com>
 
 	PR target/86076

gcc/config/arc/atomic.md

@@ -120,7 +120,7 @@
    (match_operand:SI 1 "mem_noofs_operand" "")
    (match_operand:SI 2 "register_operand" "")
    (match_operand:SI 3 "const_int_operand" "")]
-  "TARGET_ATOMIC"
+  "TARGET_ARC700 || TARGET_V2"
 {
   enum memmodel model = (enum memmodel) INTVAL (operands[3]);