[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/extractelement-legalization-store-ordering.ll b/llvm/test/CodeGen/X86/extractelement-legalization-store-ordering.ll
index 4d0b5cc..a2aa23b 100644
--- a/llvm/test/CodeGen/X86/extractelement-legalization-store-ordering.ll
+++ b/llvm/test/CodeGen/X86/extractelement-legalization-store-ordering.ll
@@ -9,7 +9,7 @@
 
 define void @test_extractelement_legalization_storereuse(<4 x i32> %a, i32* nocapture %x, i32* nocapture readonly %y, i32 %i) #0 {
 ; CHECK-LABEL: test_extractelement_legalization_storereuse:
-; CHECK:       ## BB#0: ## %entry
+; CHECK:       ## %bb.0: ## %entry
 ; CHECK-NEXT:    pushl %ebx
 ; CHECK-NEXT:    pushl %edi
 ; CHECK-NEXT:    pushl %esi