flags.  This is needed by the new legalize types
infrastructure which wants to expand the 64 bit
constants previously used to hold the flags on
32 bit machines.  There are two functional changes:
(1) in LowerArguments, if a parameter has the zext
attribute set then that is marked in the flags;
before it was being ignored; (2) PPC had some bogus
code for handling two word arguments when using the
ELF 32 ABI, which was hard to convert because of
the bogusness.  As suggested by the original author
(Nicolas Geoffray), I've disabled it for the moment.
Tested with "make check" and the Ada ACATS testsuite.

llvm-svn: 48640

field to 32 bits, thus enabling correct handling of ByVal
structs bigger than 0x1ffff.  Abstract interface a bit.
Fixes gcc.c-torture/execute/pr23135.c and 
gcc.c-torture/execute/pr28982b.c in gcc testsuite (were ICE'ing
on ppc32, quietly producing wrong code on x86-32.)

llvm-svn: 48122

llvm-svn: 46930

llvm-svn: 46002

llvm-svn: 45995

llvm-svn: 45418

llvm-svn: 40986

llvm-svn: 37640

llvm-svn: 34738

llvm-svn: 34736

llvm-svn: 34656

llvm-svn: 34655