Silence static analyzer warnings in LLVMSupport.

The static analyzer catches a few potential bugs in LLVMSupport. Add
in asserts to silence the warnings.

llvm-svn: 224044
diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index 985c877..7b06219 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -323,6 +323,7 @@
       if (i+1 >= argc)
         return Handler->error("requires a value!");
       // Steal the next argument, like for '-o filename'
+      assert(argv && "null check");
       Value = argv[++i];
     }
     break;
@@ -356,6 +357,7 @@
   while (NumAdditionalVals > 0) {
     if (i+1 >= argc)
       return Handler->error("not enough values!");
+    assert(argv && "null check");
     Value = argv[++i];
 
     if (CommaSeparateAndAddOccurrence(Handler, i, ArgName, Value, MultiArg))
diff --git a/llvm/lib/Support/ScaledNumber.cpp b/llvm/lib/Support/ScaledNumber.cpp
index fc6d4e7..725f464 100644
--- a/llvm/lib/Support/ScaledNumber.cpp
+++ b/llvm/lib/Support/ScaledNumber.cpp
@@ -169,6 +169,8 @@
   int Shift = 63 - (NewE - E);
   assert(Shift <= LeadingZeros);
   assert(Shift == LeadingZeros || NewE == ScaledNumbers::MaxScale);
+  assert((Shift & (1u << std::numeric_limits<int>::digits)) == 0 &&
+         "undefined behavior");
   D <<= Shift;
   E = NewE;