installing 7.2b3 on IRIX 6.5.13

We needed to install 7.2b3 on Irix 6.5.13 with MIPSpro Compilers:
Version 7.30
when installing as we installed 7.1.3, it is with-template=irix5 adding
to irix5 these lines:
CC=cc
CFLAGS='-n32 -O2 -r12000'
LDFLAGS='-n32 -O2 -r12000'

where -o2:

Turns on extensive optimization. The
optimizations at
this level are generally conservative, in the
sense that
they are virtually always beneficial, provide
improvements commensurate to the compile time
spent to
achieve them, and avoid changes which affect such
things
as floating point accuracy.

-r12000 specifies the processor.

and -n32: Generates a (new) 32-bit object.

it is necessary to use cc because gcc gives assembler errors

When installing 7.2b3 we receive after gmake:
len = offsetof(PgStat_MsgTabpurge, m_tableid[msg.m_nentries])
must have a constant value

I think it's because definition in stddef.h is incompatible with usage
stdef.h:
#if defined(_COMPILER_VERSION) && (_COMPILER_VERSION >= 400)
#define offsetof(t, memb) ((size_t)__INTADDR__(&(((t
*)0)->memb)))
#else
#define offsetof(s, m) (size_t)(&(((s *)0)->m))
#endif

we managed to install forcing postgres to redefine offsetof, it is
removing #ifndef offsetof
after that it installed of course giving warning in all redefinition,
but it already works.

Hope it helps