After inclusion of JDK-8248901 into OpenJDK 8u (8u312-b01), the tree fails to build on RHEL 6 and Windows. This is an 8u-specific bug. Failures look like:

/usr/bin/g++ -DLINUX -D_GNU_SOURCE -DAMD64 -DPRODUCT -I. -I/home/openjdk/jdk8u/hotspot/src/share/vm/prims -I/home/openjdk/jdk8u/hotspot/src/share/vm -I/home/openjdk/jdk8u/hotspot/src/share/vm/precompiled -I/home/openjdk/jdk8u/hotspot/src/cpu/x86/vm -I/home/openjdk/jdk8u/hotspot/src/os_cpu/linux_x86/vm -I/home/openjdk/jdk8u/hotspot/src/os/linux/vm -I/home/openjdk/jdk8u/hotspot/src/os/posix/vm -I../generated -DHOTSPOT_RELEASE_VERSION="\"25.312-b01\"" -DHOTSPOT_BUILD_TARGET="\"product\"" -DHOTSPOT_BUILD_USER="\"openjdk\"" -DHOTSPOT_LIB_ARCH=\"amd64\" -DHOTSPOT_VM_DISTRO="\"OpenJDK\"" -DTARGET_OS_FAMILY_linux -DTARGET_ARCH_x86 -DTARGET_ARCH_MODEL_x86_64 -DTARGET_OS_ARCH_linux_x86 -DTARGET_OS_ARCH_MODEL_linux_x86_64 -DTARGET_COMPILER_gcc -DINCLUDE_JFR=1 -DCOMPILER2 -DCOMPILER1 -fPIC -fno-rtti -fno-exceptions -D_REENTRANT -fcheck-new -fvisibility=hidden -m64 -pipe -fno-strict-aliasing -fno-omit-frame-pointer -O3 -g -DVM_LITTLE_ENDIAN -D_LP64=1 -Werror -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2 -Wreturn-type -fstack-protector -std=gnu++98 -DDTRACE_ENABLED -c -MMD -MP -MF ../generated/dependencies/precompiled.hpp.gch.d -fpch-deps -x c++-header /home/openjdk/jdk8u/hotspot/src/share/vm/precompiled/precompiled.hpp -o precompiled.hpp.gch
In file included from /home/openjdk/jdk8u/hotspot/src/share/vm/precompiled/precompiled.hpp:29:
/home/openjdk/jdk8u/hotspot/src/share/vm/asm/assembler.hpp: In static member function ‘static bool AbstractAssembler::is_simm(int64_t, uint)’:
/home/openjdk/jdk8u/hotspot/src/share/vm/asm/assembler.hpp:302: error: ‘INT64_C’ was not declared in this scope
/home/openjdk/jdk8u/hotspot/src/share/vm/asm/assembler.hpp: In static member function ‘static bool AbstractAssembler::is_uimm(uint64_t, uint)’:
/home/openjdk/jdk8u/hotspot/src/share/vm/asm/assembler.hpp:315: error: ‘UINT64_C’ was not declared in this scope
gmake[6]: *** [precompiled.hpp.gch] Error 1
gmake[6]: Leaving directory `/home/openjdk/jdk8u/build/release/hotspot/linux_amd64_compiler2/product'
gmake[5]: *** [the_vm] Error 2
gmake[5]: Leaving directory `/home/openjdk/jdk8u/build/release/hotspot/linux_amd64_compiler2/product'
gmake[4]: *** [product] Error 2
gmake[4]: Leaving directory `/home/openjdk/jdk8u/build/release/hotspot'
gmake[3]: *** [generic_build2] Error 2
gmake[3]: Leaving directory `/home/openjdk/jdk8u/hotspot/make'
gmake[2]: *** [product] Error 2
gmake[2]: Leaving directory `/home/openjdk/jdk8u/hotspot/make'
gmake[1]: *** [/home/openjdk/jdk8u/build/release/hotspot/_hotspot.timestamp] Error 2
gmake[1]: Leaving directory `/home/openjdk/jdk8u/make'
make: *** [hotspot-only] Error 2 

And on Windows:

C:\tmp\build-8\OJDKBU~1\tools\TOOLCH~1\vs2010e\VC\Bin\X86_AM~1\cl.exe /nologo /W3 /WX /Zi /D "_LP64" /D "AMD64" /D "WIN32" /D "_WINDOWS" /D "VM_LITTLE_ENDIAN" /D TARGET_OS_FAMILY_windows /D TARGET_ARCH_x86 /D TARGET_ARCH_MODEL_x86_64 /D TARGET_OS_ARCH_windows_x86 /D TARGET_OS_ARCH_MODEL_windows_x86_64 /D TARGET_COMPILER_visCPP /MD /D _STATIC_CPPLIB /D _DISABLE_DEPRECATE_STATIC_CPPLIB /MP /D INCLUDE_JFR=1 /O2 /Oy- /D "PRODUCT" /D "COMPILER1" /D "COMPILER2" /D "HOTSPOT_RELEASE_VERSION=\"25.312-b01\"" /D "JRE_RELEASE_VERSION=\"1.8.0_312-ea-b01\"" /D "HOTSPOT_LIB_ARCH=\"amd64\"" /D "HOTSPOT_BUILD_TARGET=\"product\"" /D "HOTSPOT_BUILD_USER=\"tester\"" /D "HOTSPOT_VM_DISTRO=\"OpenJDK\"" /I "..\generated" /I "C:\tmp\build-8\jdk8u\hotspot\src\share\vm" /I "C:\tmp\build-8\jdk8u\hotspot\src\share\vm\precompiled" /I "C:\tmp\build-8\jdk8u\hotspot\src\share\vm\prims" /I "C:\tmp\build-8\jdk8u\hotspot\src\os\windows\vm" /I "C:\tmp\build-8\jdk8u\hotspot\src\os_cpu\windows_x86\vm" /I "C:\tmp\build-8\jdk8u\hotspot\src\cpu\x86\vm" /D "_JNI_IMPLEMENTATION_" /Fp"vm.pch" /Yc"precompiled.hpp" /c ../generated/_build_pch_file.cpp
_build_pch_file.cpp
C:\tmp\build-8\jdk8u\hotspot\src\share\vm\asm/assembler.hpp(302) : error C3861: 'INT64_C': identifier not found
C:\tmp\build-8\jdk8u\hotspot\src\share\vm\asm/assembler.hpp(315) : error C3861: 'UINT64_C': identifier not found
NMAKE : fatal error U1077: 'C:\tmp\build-8\OJDKBU~1\tools\TOOLCH~1\vs2010e\VC\Bin\X86_AM~1\cl.exe' : return code '0x2'
Stop.
NMAKE : fatal error U1077: 'cd' : return code '0x2'
Stop.
NMAKE : fatal error U1077: 'C:\tmp\build-8\ojdkbuild\tools\toolchain\vs2010e\VC\Bin\nmake.EXE' : return code '0x2'
Stop.
make[3]: *** [Makefile:231: generic_build2] Error 2
make[3]: Leaving directory '/cygdrive/c/tmp/build-8/jdk8u/hotspot/make'
make[2]: Leaving directory '/cygdrive/c/tmp/build-8/jdk8u/hotspot/make'
make[1]: Leaving directory '/cygdrive/c/tmp/build-8/jdk8u/make'
make[2]: *** [Makefile:177: product] Error 2
make[1]: *** [HotspotWrapper.gmk:45: /cygdrive/c/tmp/build-8/jdk8u/build/windows-x86_64-server-release/hotspot/_hotspot.timestamp] Error 2
make: *** [/cygdrive/c/tmp/build-8/jdk8u//make/Main.gmk:110: hotspot-only] Error 2