[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/Mips/prevent-hoisting.ll b/llvm/test/CodeGen/Mips/prevent-hoisting.ll
index ca71bf7..1fc7462 100644
--- a/llvm/test/CodeGen/Mips/prevent-hoisting.ll
+++ b/llvm/test/CodeGen/Mips/prevent-hoisting.ll
@@ -16,7 +16,7 @@
 ; CHECK:           sll
 
 ; Check that at the start of a fallthrough block there is a instruction that writes to $1.
-; CHECK:       {{BB[0-9_#]+}}:
+; CHECK:       {{%bb.[0-9]+}}:
 ; CHECK:           sll $1, $[[R0:[0-9]+]], 4
 ; CHECK:           lw      $[[R1:[0-9]+]], %got(assignSE2partition)($[[R2:[0-9]+]])