[10] RFR: 8171813: possible null pointer dereference defects

[Rahul Raghavan]

Hi,

Please review following patch proposal to avoid 
possible null pointer dereference warnings / errors for internal tests.

<webrev.00> - http://cr.openjdk.java.net/~rraghavan/8171813/webrev.00/


<jbs> -  https://bugs.openjdk.java.net/browse/JDK-8171813

-- Reported issue - possible null pointer dereference warnings / errors for internal tests,
due to the case that 'function CompileBroker::compiler - hotspot/src/share/vm/compiler/compileBroker.hpp, may return NULL'
  
-- Above <webrev.00> fix proposal is to add explicit check in following reported locations
  - Compile::make_vm_intrinsic - hotspot/src/share/vm/opto/library_call.cpp
  - SimpleThresholdPolicy::is_trivial - hotspot/src/share/vm/runtime/simpleThresholdPolicy.inline.hpp
  - CompileBroker::compile_method - hotspot/src/share/vm/compiler/compileBroker.cpp

-- Confirmed no issues with testing -  jprt run (-testset hotspot).

Thanks,
Rahul