Given my previous fix for a missing insn pattern for e500, building
glibc runs into an assembler error "Error: operand out of range (256
is not between 0 and 248)".  This comes from an insn:

(insn 115 1209 1210 (set (reg:DF 27 27 [orig:294 _129 ] [294])
        (subreg:DF (mem/c:TI (plus:SI (reg/f:SI 1 1)
                    (const_int 256 [0x100])) [14 %sfp+256 S16 A128]) 0)) 1909 {*frob_df_ti}
     (nil))

This patch adjusts the offset handling for TImode - and TDmode and
PTImode in case such subregs can arise for them - to be the same as
for TFmode, so that proper SPE offset checks are made in the
TARGET_E500_DOUBLE case.

This allows the glibc build to complete.  Testing shows 372 FAILs
across the gcc, g++ and libstdc++ testsuites; more cleanup is
certainly needed, but this gets to the point where the toolchain at
least builds so it's possible to compare test results when fixing
bugs.

	* config/rs6000/rs6000.c (rs6000_legitimate_offset_address_p): For
	TARGET_E500_DOUBLE. handle TDmode, TImode and PTImode the same as
	TFmode, IFmode and KFmode.

From-SVN: r242814