Make some LLVM_CONSTEXPR variables const. NFC.

This patch changes LLVM_CONSTEXPR variable declarations to const
variable declarations, since LLVM_CONSTEXPR expands to nothing if the
current compiler doesn't support constexpr. In all of the changed
cases, it looks like the code intended the variable to be const instead
of sometimes-constexpr sometimes-not.

llvm-svn: 279696
diff --git a/llvm/lib/Analysis/AliasAnalysisSummary.h b/llvm/lib/Analysis/AliasAnalysisSummary.h
index 18ca3a9..51a85f4 100644
--- a/llvm/lib/Analysis/AliasAnalysisSummary.h
+++ b/llvm/lib/Analysis/AliasAnalysisSummary.h
@@ -99,7 +99,7 @@
 //===----------------------------------------------------------------------===//
 
 /// The maximum number of arguments we can put into a summary.
-LLVM_CONSTEXPR static unsigned MaxSupportedArgsInSummary = 50;
+static const unsigned MaxSupportedArgsInSummary = 50;
 
 /// We use InterfaceValue to describe parameters/return value, as well as
 /// potential memory locations that are pointed to by parameters/return value,
@@ -137,7 +137,7 @@
 // We use UnknownOffset to represent pointer offsets that cannot be determined
 // at compile time. Note that MemoryLocation::UnknownSize cannot be used here
 // because we require a signed value.
-static LLVM_CONSTEXPR int64_t UnknownOffset = INT64_MAX;
+static const int64_t UnknownOffset = INT64_MAX;
 
 inline int64_t addOffset(int64_t LHS, int64_t RHS) {
   if (LHS == UnknownOffset || RHS == UnknownOffset)