[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/AMDGPU/else.ll b/llvm/test/CodeGen/AMDGPU/else.ll
index 22338e4..c73ea93 100644
--- a/llvm/test/CodeGen/AMDGPU/else.ll
+++ b/llvm/test/CodeGen/AMDGPU/else.ll
@@ -25,7 +25,7 @@
 }
 
 ; CHECK-LABEL: {{^}}else_execfix_leave_wqm:
-; CHECK: ; BB#0:
+; CHECK: ; %bb.0:
 ; CHECK-NEXT: s_mov_b64 [[INIT_EXEC:s\[[0-9]+:[0-9]+\]]], exec
 ; CHECK: ; %Flow
 ; CHECK-NEXT: s_or_saveexec_b64 [[DST:s\[[0-9]+:[0-9]+\]]],