[10] RFR(XS) 8185013: Disable subword vector analysis optimization until 8184995 is fixed

[Vladimir Kozlov]

https://bugs.openjdk.java.net/browse/JDK-8185013

Switch UseSubwordForMaxVector flag off by default.

src/share/vm/opto/c2_globals.hpp
@@ -192,7 +192,7 @@
            "of rounds of unroll,optimize,..")                          \
            range(0, max_jint)                                          \
                                                                        \
-  product(bool, UseSubwordForMaxVector, true,                         \
+  product(bool, UseSubwordForMaxVector, false,                        \
            "Use Subword Analysis to set maximum vector size")          \
                                                                        \
    develop(intx, UnrollLimitForProfileCheck, 1,                        \

Thanks,
Vladimir