JDK-8139040 enables -Wuninitialized on linux. It breaks the build in our repo and we can't push to hs-main:

/oracle/8141629/hotspot/src/share/vm/opto/library_call.cpp: In member function ‘bool LibraryCallKit::inline_string_copy(bool)’:
/oracle/8141629/hotspot/src/share/vm/opto/library_call.cpp:1268:37: error: ‘count’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     set_result(_gvn.transform(count));

/oracle/8141629/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp: In member function ‘void MacroAssembler::string_compare(Register, Register, Register, Register, Register, XMMRegister, int)’:
/oracle/8141629/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp:7037:82: error: ‘scale’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     load_next_elements(result, cnt2, str1, str2, scale, scale1, scale2, cnt1, ae);