In hotspot/make/bsd/makefiles/gcc.make, we check the clang version to decide whether to apply the optimization bug [0] workaround. Doing it this way forces us to repeatedly update the build file every time we use a new toolchain version. As part of the new HotSpot build system (see jdk8152666), this check was finally removed in JDK 9. While it would be inappropriate to try and backport the entire new build system to JDK 8, we do need a long-term fix for this Xcode version check. I propose we remove the version check from JDK 8 gcc.make file to bring its behavior in line with JDK 9 and later.

BTW, I have tested [1] and confirmed that we still need to disable optimization on both loopTransform.o and unsafe.o with toolchain as recent as Xcode 11.3.

[0] I've never actually found any evidence that these two issues are in fact the result of clang bugs as opposed to bugs in our own code. Perhaps something to investigate in the future.

[1]
jdk/test/sun/misc/CopyMemory.java
hotspot/test/compiler/c2/5091921/