RFR: 8256757: Incorrect MachCallRuntimeNode::ret_addr_offset() for CallLeafNoFP on x86_32

[Aleksey Shipilev]

JDK-8254231 added new assert in `output.cpp`:

    assert(!is_mcall || (call_returns[block->_pre_order] <= (uint) current_offset))

Which verifies that the offset returned by MachCallNode::ret_addr_offset() (and sub-types) at matches the emitted code, to avoid potential conflicts between oop maps of different calls.

It caught the failure running `compiler/intrinsics/string/TestStringLatin1IndexOfChar.java` on Linux x86_32, because it forces lower SSE settings. But more tests fail if you run with lower SSE settings. The real issue is `MachCallRuntimeNode::ret_addr_offset()` computing the offset incorrectly for `CallLeafNoFP`: the match rule for it does not include `FFree_Float_Stack_All`.

See the definitions:

// Call runtime without safepoint
instruct CallLeafDirect(method meth) %{
  match(CallLeaf);
  effect(USE meth);

  ins_cost(300);
  format %{ "CALL_LEAF,runtime " %}
  opcode(0xE8); /* E8 cd */
  ins_encode( pre_call_resets,
              FFree_Float_Stack_All,
              Java_To_Runtime( meth ),
              Verify_FPU_For_Leaf, post_call_FPU );
  ins_pipe( pipe_slow );
%}

instruct CallLeafNoFPDirect(method meth) %{
  match(CallLeafNoFP);
  effect(USE meth);

  ins_cost(300);
  format %{ "CALL_LEAF_NOFP,runtime " %}
  opcode(0xE8); /* E8 cd */
  ins_encode(pre_call_resets, Java_To_Runtime(meth));
  ins_pipe( pipe_slow );
%}


Testing:
 - [x] A few known failing tests on Linux x86_32
 - [x] Linux x86_32 `tier1`
 - [ ] Linux x86_32 `tier1` with `-UseSSE=1`

-------------

Commit messages:
 - Formatting, comments
 - 8256757: Incorrect MachCallRuntimeNode::ret_addr_offset() for CallLeafNoFP

Changes: https://git.openjdk.java.net/jdk/pull/1452/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1452&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256757
  Stats: 9 lines in 5 files changed: 7 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1452.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1452/head:pull/1452

PR: https://git.openjdk.java.net/jdk/pull/1452