Fixes for PPC host detection and features.

POWER4 is a 64-bit CPU (better matched to the 970).
The g3 is really the 750 (no altivec), the g4+ is the 74xx (not the 750).

Patch by Andreas Tobler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158363 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Host.cpp b/lib/Support/Host.cpp
index d48c526..677da5c 100644
--- a/lib/Support/Host.cpp
+++ b/lib/Support/Host.cpp
@@ -440,7 +440,7 @@
     .Case("7447", "7400")
     .Case("7455", "7450")
     .Case("G4", "g4")
-    .Case("POWER4", "g4")
+    .Case("POWER4", "970")
     .Case("PPC970FX", "970")
     .Case("PPC970MP", "970")
     .Case("G5", "g5")