RFR: 8365231: Don't build gtest with /EHsc

[Magnus Ihse Bursie]

According to https://github.com/openjdk/jdk/pull/26661#issuecomment-3162014034, we should not build gtest with `/EHsc`. 

I can honestly say I don't fully understand the consequences of this change, but at least it passes building and testing on Oracle CI. And it does seem to make sense that we build the gtest version of libjvm as close as possible to the real version. For libgtest I just thought it was prudent to keep the flags in sync with how we build libjvm. This might not be the correct decision.

I have not tested how or if this affects the ability for gtest to handle bugs or crashes in the JVM, nor do I really have any idea about any such consequences. This PR is opened more to start a discussion than with the intention of just integrating this.

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Commit messages:
 - 8365231: Don't build gtest with /EHsc

Changes: https://git.openjdk.org/jdk/pull/26721/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26721&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365231
  Stats: 4 lines in 1 file changed: 1 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/26721.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26721/head:pull/26721

PR: https://git.openjdk.org/jdk/pull/26721