[9] RFR(XS): 8008321: compile.cpp verify_graph_edges uses "bool" as "int"

[Tobias Hartmann]

Hi,

please review the following small patch that fixes the type of the dead 
nodes counter in Compile::verify_graph_edges(..).

Bug: https://bugs.openjdk.java.net/browse/JDK-8008321
Webrev: http://cr.openjdk.java.net/~thartmann/8008321/webrev.00/
Testing: JPRT

Thanks,
Tobias