RFR(S): 8211232: GraphKit::make_runtime_call() sometimes attaches wrong memory state to call

[Roland Westrelin]

http://cr.openjdk.java.net/~roland/8211232/webrev.00/

This came up in shenandoah testing with XX:+ExtendedDTraceProbes. 

make_runtime_call() is called through make_dtrace_method_exit() from
Parse::return_current(). Memory state at this point is:

 137 Phi === 135 _ _ 91 [[ 74 141 145 150 152 162 166 168 179 182 187 193 202 211 216 225 228 237 242 258 266 274 282 ]] #memory Memory: @BotPTR *+bot, idx=Bot; !jvms: IdentityHashMap::put @ bci:24 
 141 MergeMem === _ 1 137 1 1 279 1 275 282 [[ 142 ]] { - - N279:java/lang/Object+-8 * - N275:narrowoop: java/lang/Object *[int:>=0]+-8 * N282:narrowoop: java/lang/Object *[int:>=0]+any * [narrow] } Memory: @BotPTR *+bot, idx=Bot; !jvms: IdentityHashMap::put @ bci:24 

The Phi is a loop phi so not all its inputs are set yet. The following
code in GraphKit::make_runtime_call():

    assert(!wide_out, "narrow in => narrow out"); 
    Node* narrow_mem = memory(adr_type); 
    prev_mem = reset_memory(); 
    map()->set_memory(narrow_mem); 

set the entire memory state to the phi. Next in
GraphKit::set_predefined_input_for_runtime_call():

  Node* memory = reset_memory(); 

causes the current memory state (the Phi) to be transformed which the
GVN transforms to:

 91 Phi === 89 _ _ 73 [[ 137 100 103 105 113 116 118 126 129 131 ]] #memory Memory: @BotPTR *+bot, idx=Bot; !jvms: IdentityHashMap::put @ bci:24 

the out of loop memory state and so the wrong state.

Roland.