RFR: 8375046: C2: Assertion failed in GrowableArray::remove_till(0)

[Aleksey Shipilev]

Seen this assert in stress CTW runs:


# Internal Error (/home/shade/trunks/jdk/src/hotspot/share/utilities/growableArray.hpp:498), pid=2972347, tid=2973775
# assert(start < end && end <= this->_len) failed: erase called with invalid range (0, 0) for length 0

Stack: [0x00007fd660bea000,0x00007fd660cea000], sp=0x00007fd660ce4fc0, free space=1003k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xc00a41] Compile::inline_incrementally_one()+0x801 (growableArray.hpp:498)
V [libjvm.so+0xc01650] Compile::inline_incrementally(PhaseIterGVN&)+0x2f0 (compile.cpp:2212)
V [libjvm.so+0xc04581] Compile::Optimize()+0x7d1 (compile.cpp:2357) 


It looks innocuous, as `GrowableArray::remove_range` does nothing real on `[0, 0)`. It is still IMO a bug to call it with `[0, 0)`, as it is not clear whether to trust inclusive or exclusive boundary. But for `remove_till`, it looks plausible that `remove_till(0)` should work and be a no-op.

Additional testing:
 - [x] Linux x86_64 server fastdebug, new gtest used to fail without the fix, now passes

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

Commit messages:
 - No trailing comma
 - Fix

Changes: https://git.openjdk.org/jdk/pull/29171/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29171&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375046
  Stats: 84 lines in 2 files changed: 82 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29171.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29171/head:pull/29171

PR: https://git.openjdk.org/jdk/pull/29171