TargetLowering: Fix InitLibcallCallingConvs() overriding things set in InitLibcalls()

I missed the fact that the later called InitLibcallCallingConvs()
overrides some things set in InitLibcalls() when I did the refactoring
in r321036.

Fix by merging InitLibcallCallingConvs() into InitLibcalls() and doing
the initialization earlier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321045 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed