Quick fix:

sed_repl 's:  if test -s "$OCI8_DIR/orainst/unix.rgs"; then:'\
'  if test -s "$OCI8_LCS_BASE.11.2"; then\n    OCI8_ORACLE_VERSION=11.2;\n'\
'  elif test -s "$OCI8_DIR/orainst/unix.rgs"; then:' configure

Instead of patching the configuration script can you try creating a symbolic 
link from libclntsh.so and/or libclntsh.so.11.1 pointing to libclntsh.so.11.2?

For ORACLE_HOME installs on Linux (and likely on Solaris) a symbolic link from 
libclntsh.so to libclntsh.so.11.1 is automatically created during Oracle 
installation.

Linux & Solaris 11.2 Instant Client zip installs provide libclntsh.so.11.1 (for 
drop-in library replacement similar to how Oracle 10.2 libs were called *.10.1). 
Generic installation instructions for Instant Client are to manually create a 
symbolic link from libclntsh.so to libclntsh.so.11.1

It might work, but I wouldn't want to hack around in the Oracle's directory... could you please add an option to ./configure prevent the version-autodetecting? Something like: 

OCI8_VERSION=11.2 ./configure --with-oci8

or

export OCI8_VERSION="$(grep OCI_MAJOR_VERSION $ORACLE_HOME/rdbms/public/oci.h | cut -d' ' -f 4).$(grep OCI_MINOR_VERSION $ORACLE_HOME/rdbms/public/oci.h | cut -d' ' -f 4)"
./configure --with-oci8

What created libclntsh.so.11.2?  The instantclient-basic-aix.ppc64-
11.2.0.3.0.zip 
and instantclient-basic-aix.ppc32-11.2.0.3.0.zip files only contain libclntsh.so

I don't consider creating a libcntsh.so.11.1 symlink such a hack, since creating 
the reverse symlink is required on other platforms.  See 
http://docs.oracle.com/cd/E11882_01/appdev.112/e10646/oci01int.htm#LNOCI16174
However I can improve the installation experience on AIX once I understand what 
the installed environment commonly looks like.

A new aspect of this problem: an over-zealous version of 'tail' wouldn't accept syntax 'tail -1' only 'tail -n1'

(in this line in configure:
  OCI8_LCS=`ls $OCI8_LCS_BASE.*.1 2> /dev/null | tail -1`  # Oracle 10g, 11g etc
)

I merged the "tail" fix.  I'm closing this bug out.  I understand you'll need to 
create a symlink like other platforms.

Okay, thank you for your help.

The tail "fix" breaks compilation on Solaris for php version 5.3.18, which worked until version 5.3.17.

Not all "tail" implementations support "-n1". On Solaris default "tail" only support "-1".

You could switch to using a variable TAIL and auto detect a working tail implementation (understanding "-n"), which on Solaris would be the non standard /usr/xpg4/bin/tail. Users could overwrite with a new --with-tail switch.

I re-fixed this and also pushed OCI8 1.4.9 with the fix to PECL.

I couldn't find 1.4.9 but I agree with the patch by rading and understanding it and also applied the patch and tested it successful on Solaris and Linux. Thanks for your quick fix!

Sorry "rading" meant "reading" (typo). 1.4.9 looks fine. Thanks again.