[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/X86/pr32340.ll b/llvm/test/CodeGen/X86/pr32340.ll
index dd160c6..f5a67c1 100644
--- a/llvm/test/CodeGen/X86/pr32340.ll
+++ b/llvm/test/CodeGen/X86/pr32340.ll
@@ -12,7 +12,7 @@
 
 define void @foo() {
 ; X64-LABEL: foo:
-; X64:       # BB#0: # %entry
+; X64:       # %bb.0: # %entry
 ; X64-NEXT:    xorl %eax, %eax
 ; X64-NEXT:    movl %eax, %ecx
 ; X64-NEXT:    movabsq $-1142377792914660288, %rdx # imm = 0xF02575732E06E440