Unify XDEBUG and EXPENSIVE_CHECKS (into the latter), and add an option to the cmake build to enable them.

Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.

This will also make it easier to turn it on in buildbots.

Reviewers: chandlerc

Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits

Differential Revision: http://reviews.llvm.org/D19723

llvm-svn: 268050
diff --git a/llvm/lib/Target/ARM/ARMFrameLowering.cpp b/llvm/lib/Target/ARM/ARMFrameLowering.cpp
index 909a728..808a21f 100644
--- a/llvm/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMFrameLowering.cpp
@@ -2155,7 +2155,7 @@
 
   PrevStackMBB->addSuccessor(McrMBB);
 
-#ifdef XDEBUG
+#ifdef EXPENSIVE_CHECKS
   MF.verify();
 #endif
 }
diff --git a/llvm/lib/Target/Hexagon/HexagonCommonGEP.cpp b/llvm/lib/Target/Hexagon/HexagonCommonGEP.cpp
index 2258f22..c087b72 100644
--- a/llvm/lib/Target/Hexagon/HexagonCommonGEP.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonCommonGEP.cpp
@@ -1298,7 +1298,7 @@
   materialize(Loc);
   removeDeadCode();
 
-#ifdef XDEBUG
+#ifdef EXPENSIVE_CHECKS
   // Run this only when expensive checks are enabled.
   verifyFunction(F);
 #endif
diff --git a/llvm/lib/Target/Sparc/SparcFrameLowering.cpp b/llvm/lib/Target/Sparc/SparcFrameLowering.cpp
index 5e1e61e..87b0155 100644
--- a/llvm/lib/Target/Sparc/SparcFrameLowering.cpp
+++ b/llvm/lib/Target/Sparc/SparcFrameLowering.cpp
@@ -350,7 +350,7 @@
   }
 
   assert(verifyLeafProcRegUse(&MRI));
-#ifdef XDEBUG
+#ifdef EXPENSIVE_CHECKS
   MF.verify(0, "After LeafProc Remapping");
 #endif
 }
diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 155cb3c..8a28377 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -2279,7 +2279,7 @@
   checkMBB->addSuccessor(allocMBB);
   checkMBB->addSuccessor(&PrologueMBB);
 
-#ifdef XDEBUG
+#ifdef EXPENSIVE_CHECKS
   MF.verify();
 #endif
 }
@@ -2423,7 +2423,7 @@
     incStackMBB->addSuccessor(&PrologueMBB, {99, 100});
     incStackMBB->addSuccessor(incStackMBB, {1, 100});
   }
-#ifdef XDEBUG
+#ifdef EXPENSIVE_CHECKS
   MF.verify();
 #endif
 }