Fix PR15632: No support for ppcf128 floating-point remainder on PowerPC.

For this we need to use a libcall.  Previously LLVM didn't implement
libcall support for frem, so I've added it in the usual
straightforward manner.  A test case from the bug report is included.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178639 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/PowerPC/pr15632.ll

@@ -0,0 +1,15 @@
+; RUN: llc -mcpu=pwr7 -O0 < %s | FileCheck %s
+
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+declare void @other(ppc_fp128 %tmp70)
+
+define void @bug() {
+entry:
+  %tmp70 = frem ppc_fp128 0xM00000000000000000000000000000000, undef
+  call void @other(ppc_fp128 %tmp70)
+  unreachable
+}
+
+; CHECK: bl fmodl