[CodeGen] Unify MBB reference format in both MIR and debug output

As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
diff --git a/llvm/test/CodeGen/PowerPC/2006-07-07-ComputeMaskedBits.ll b/llvm/test/CodeGen/PowerPC/2006-07-07-ComputeMaskedBits.ll
index 56f4a41..5b8b814 100644
--- a/llvm/test/CodeGen/PowerPC/2006-07-07-ComputeMaskedBits.ll
+++ b/llvm/test/CodeGen/PowerPC/2006-07-07-ComputeMaskedBits.ll
@@ -6,7 +6,7 @@
 
 define i32 @test(i32 %i) {
 ; CHECK-LABEL: test:
-; CHECK:       # BB#0:
+; CHECK:       # %bb.0:
 ; CHECK-NEXT:    addis 4, 2, .LC0@toc@ha
 ; CHECK-NEXT:    extsw 3, 3
 ; CHECK-NEXT:    addis 5, 2, .LC1@toc@ha