[CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.

Work towards the unification of MIR and debug output by refactoring the
interfaces.

For MachineOperand::print, keep a simple version that can be easily called
from `dump()`, and a more complex one which will be called from both the
MIRPrinter and MachineInstr::print.

Add extra checks inside MachineOperand for detached operands (operands
with getParent() == nullptr).

https://reviews.llvm.org/D40836

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g'

llvm-svn: 320022
diff --git a/llvm/test/CodeGen/AVR/select-must-add-unconditional-jump.ll b/llvm/test/CodeGen/AVR/select-must-add-unconditional-jump.ll
index 5c247f6..a0116d6 100644
--- a/llvm/test/CodeGen/AVR/select-must-add-unconditional-jump.ll
+++ b/llvm/test/CodeGen/AVR/select-must-add-unconditional-jump.ll
@@ -11,11 +11,11 @@
 ;
 ; %bb.2: derived from LLVM BB %finish
 ;     Predecessors according to CFG: %bb.0 %bb.1
-;         %0<def> = PHI %3, <%bb.0>, %5, <%bb.1>
-;         %7<def> = LDIRdK 2
-;         %8<def> = LDIRdK 1
-;         CPRdRr %2, %0, %SREG<imp-def>
-;         BREQk <%bb.6>, %SREG<imp-use>
+;         %0 = PHI %3, <%bb.0>, %5, <%bb.1>
+;         %7 = LDIRdK 2
+;         %8 = LDIRdK 1
+;         CPRdRr %2, %0, implicit-def %SREG
+;         BREQk <%bb.6>, implicit %SREG
 ;     Successors according to CFG: %bb.5(?%) %bb.6(?%)
 ;
 ; The code assumes it the fallthrough block after this is %bb.5, but