32-bit compilation fails when using AIX and Open XLC

[davidjmccann]

I'm trying to build OMR 0.4.0 on AIX using configure/make.

Having worked around a number of issues I've managed to get it to build 64-bit using Open XLC 17.1.

However 32-bit compilation seems to have additional issues.

rules.aix.mk seems to be missing sections when OMR_ENV_DATA64 == 0.

And then gettimebase.c also fails in this way:
/opt/IBM/openxlC/17.1.1/bin/ibm-clang -DICOL -DAMQ_INTERNAL_BUILD -I. -I../../include_core -I../../nls -D_XOPEN_SOURCE_EXTENDED=1 -D_ALL_SOURCE -DRS6000 -DAIXPPC -D_LARGE_FILES -c -m32 -mcp
u=power7 -fno-strict-aliasing -std=c89 -O0 -g -DICOL -DAMQ_INTERNAL_BUILD -o gettimebase.o gettimebase.c
gettimebase.c:75:3: error: use of undeclared identifier 'asm'
asm volatile("mftbu %0" : "=r" (upper));
^
gettimebase.c:76:3: error: use of undeclared identifier 'asm'
asm volatile("mftb %0" : "=r" (lower));
^
gettimebase.c:77:3: error: use of undeclared identifier 'asm'
asm volatile("mftbu %0" : "=r" (upper2));
^
3 errors generated.

Again, there's no corresponding section for Open XLC when #if !defined(OMR_ENV_DATA64)...