When placing constant islands and adjusting for alignment padding, inline

When placing constant islands and adjusting for alignment padding, inline
assembly can confuse things utterly, as it's assumed that instructions in
inline assembly are 4 bytes wide. For Thumb mode, that's often not true,
so the calculations for when alignment padding will be present get thrown off,
ultimately leading to out of range constant pool entry references. Making
more conservative assumptions that padding may be necessary when inline asm
is present avoids this situation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89403 91177308-0d34-0410-b5e6-96231b3b80d8