After JDK-8282191, building with AIX 7.1 results in:

ld: 0711-318 ERROR: Undefined symbols were found.
        The following symbols are in error:
 Symbol Inpndx TY CL Source-File(Object-File) OR Import-File{Shared-object}
                              RLD: Address Section Rld-type Referencing Symbol
 ----------------------------------------------------------------------------------------------
 .__pt_atexit_np [1714] ER PR /home/hotspot/openjdk/jdk-fork/src/hotspot/share/prims/universalUpcallHandler.cpp(/home/hotspot/openjdk/jdk-fork/build/aix-ppc64-server-fastdebug/hotspot/variant-server/libjvm/objs/universalUpcallHandler.o)
                                   00000050 .text R_RBR [1160] <.__tls_init>
ER: The return code is 8.

This is a known issue with XL C. See Note 2 at [1].

According to [2] the min support version of AIX is 7.2. However, if a suitable workaround could be found, I'm sure it would be well received.

[1] https://www.ibm.com/docs/en/xl-c-and-cpp-aix/16.1?topic=end-language-standard-features
[2] https://wiki.openjdk.java.net/display/Build/Supported+Build+Platforms