Move some debug testcases to the debug info directory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189418 91177308-0d34-0410-b5e6-96231b3b80d8
Use DW_FORM_sdata for signed constant values and udata on occasion
when we can. Migrate from using blocks when we're adding just a
single attribute and floating point values are an unsigned, not signed,
bag of bits.

Update all test cases accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189419 91177308-0d34-0410-b5e6-96231b3b80d8