[CodeGen] Print global addresses as @foo in both MIR and debug output

Work towards the unification of MIR and debug output by printing
`@foo` instead of `<ga:@foo>`.

Also print target flags in the MIR format since most of them are used on
global address operands.

Only debug syntax is affected.

llvm-svn: 320682
diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
index 1eb798c..15e4575 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -2316,7 +2316,7 @@
       // For a method return value, we check the ZExt/SExt flags in attribute.
       // We assume the following code sequence for method call.
       //   ADJCALLSTACKDOWN 32, implicit dead %r1, implicit %r1
-      //   BL8_NOP <ga:@func>,...
+      //   BL8_NOP @func,...
       //   ADJCALLSTACKUP 32, 0, implicit dead %r1, implicit %r1
       //   %5 = COPY %x3; G8RC:%5
       if (SrcReg == PPC::X3) {