ARM64: always restore regexp register cache after a C function call.

test/mjsunit/regress/regress-regexp-nocase.js

Index: test/mjsunit/regress/regress-regexp-nocase.js
diff --git a/test/mjsunit/regress/regress-352059.js b/test/mjsunit/regress/regress-regexp-nocase.js
similarity index 95%
copy from test/mjsunit/regress/regress-352059.js
copy to test/mjsunit/regress/regress-regexp-nocase.js
index cd1a4c28f77f40e3932b4dd860c803915b25b375..27637da0913701642fa3af097b83d383b41c0fb5 100644
--- a/test/mjsunit/regress/regress-352059.js
+++ b/test/mjsunit/regress/regress-regexp-nocase.js
@@ -25,11 +25,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-var foo = false;
+var s = "('')x\nx\uF670";
 
-function bar() {
-  foo = 2;
-  return 4 % foo;
-}
-
-bar();
+assertEquals(s.match(/\((').*\1\)/i), ["('')", "'"]);