Code refactoring: replace NULL by nullptr for pointers.

This is the frist change to replace NULL by nullptr.
It handles the initialization and assignment for pointers.

BUG=angleproject:2001

Change-Id: I6d4bb198a72e38b867cd2f65a6e6f2f61339a0b5
Reviewed-on: https://chromium-review.googlesource.com/481600
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/translator/OutputHLSL.cpp b/src/compiler/translator/OutputHLSL.cpp
index c0129da..b95f0ec 100644
--- a/src/compiler/translator/OutputHLSL.cpp
+++ b/src/compiler/translator/OutputHLSL.cpp
@@ -131,7 +131,7 @@
     mInsideDiscontinuousLoop = false;
     mNestedLoopDepth         = 0;
 
-    mExcessiveLoopIndex = NULL;
+    mExcessiveLoopIndex = nullptr;
 
     mStructureHLSL       = new StructureHLSL;
     mUniformHLSL         = new UniformHLSL(mStructureHLSL, outputType, uniforms);
@@ -2317,7 +2317,7 @@
 
     // Parse loops of the form:
     // for(int index = initial; index [comparator] limit; index += increment)
-    TIntermSymbol *index = NULL;
+    TIntermSymbol *index = nullptr;
     TOperator comparator = EOpNull;
     int initial          = 0;
     int limit            = 0;
@@ -2472,7 +2472,7 @@
 
                 if (iterations <= MAX_LOOP_ITERATIONS)  // Last loop fragment
                 {
-                    mExcessiveLoopIndex = NULL;  // Stops setting the Break flag
+                    mExcessiveLoopIndex = nullptr;  // Stops setting the Break flag
                 }
 
                 // for(int index = initial; index < clampedLimit; index += increment)