[Alignment][NFC] Remove LogAlignment functions

Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, MaskRay, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67620

llvm-svn: 372231
diff --git a/llvm/lib/CodeGen/BranchRelaxation.cpp b/llvm/lib/CodeGen/BranchRelaxation.cpp
index 3abfd14..bf7365b 100644
--- a/llvm/lib/CodeGen/BranchRelaxation.cpp
+++ b/llvm/lib/CodeGen/BranchRelaxation.cpp
@@ -127,9 +127,8 @@
 #ifndef NDEBUG
   unsigned PrevNum = MF->begin()->getNumber();
   for (MachineBasicBlock &MBB : *MF) {
-    unsigned LogAlign = MBB.getLogAlignment();
-    unsigned Num = MBB.getNumber();
-    assert(BlockInfo[Num].Offset % (1u << LogAlign) == 0);
+    const unsigned Num = MBB.getNumber();
+    assert(isAligned(MBB.getAlignment(), BlockInfo[Num].Offset));
     assert(!Num || BlockInfo[PrevNum].postOffset(MBB) <= BlockInfo[Num].Offset);
     assert(BlockInfo[Num].Size == computeBlockSize(MBB));
     PrevNum = Num;