Fix gcc.c-torture/compile/920520-1.c by inserting bitconverts

Fix gcc.c-torture/compile/920520-1.c by inserting bitconverts
for strange asm conditions earlier.  In this case, we have a
double being passed in an integer reg class.  Convert to like
sized integer register so that we allocate the right number
for the class (two i32's for the f64 in this case).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57862 91177308-0d34-0410-b5e6-96231b3b80d8