Mterp/arm: Add CFI directives.

Includes reworking of float_to_long and double_to_long to
elminate frame (as suggested by vmarko).

Test: m ART_TEST_INTERPRETER=true test-art-target (in progress)
Bug: 31456348
Change-Id: Ic4e985b977f76c4df926559b187d92d969206514
diff --git a/runtime/interpreter/mterp/arm/footer.S b/runtime/interpreter/mterp/arm/footer.S
index cd32ea2..c6801e5 100644
--- a/runtime/interpreter/mterp/arm/footer.S
+++ b/runtime/interpreter/mterp/arm/footer.S
@@ -294,6 +294,5 @@
     mov     r0, rINST                               @ restore return value
     ldmfd   sp!, {r3-r10,fp,pc}                     @ restore 10 regs and return
 
-    .fnend
-    .size   ExecuteMterpImpl, .-ExecuteMterpImpl
+    END ExecuteMterpImpl