[8u40] RFR(s) backport fixes 8046698, 8054224, 8055946

[Vladimir Kozlov]

Collection of small fixes which Roland pushed into jdk9 last month.
All are applied cleanly to jdk8u.

8046698: assert(false) failed: only Initialize or AddP expected macro.cpp:943
https://bugs.openjdk.java.net/browse/JDK-8046698
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/c82d0e6f53cd
http://cr.openjdk.java.net/~roland/8046698/webrev.01/

8054224: Recursive method that was compiled by C1 is unable to catch StackOverflowError
https://bugs.openjdk.java.net/browse/JDK-8054224
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/db7d2f27bcb6
http://cr.openjdk.java.net/~roland/8054224/webrev.00/

8055946: assert(result == NULL || result->is_oop()) failed: must be oop
https://bugs.openjdk.java.net/browse/JDK-8055946
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/df76aa0bf77f
http://cr.openjdk.java.net/~roland/8055946/webrev.00/

Thanks,
Vladimir