Do not insert prototypes in the middle of a line.

The insertion point of prototypes may be detected to be in the middle
of a line for example in the following sketch:

   int a; int b=forwardDeclared();
   void setup() {}
   void loop() {}
   int forwardDeclared() { return 0; }

the insertion point is determined to be between `int a;` and `int b=..`
since the latter declaration use a forward-declared function to
initialize variable.
Before this patch this resulted in a stray `#line` directive inserted in
the middle of a line:

   int a; #line 1 ......     <- added prototype line
   int forwardDeclared();    <- added prototype
   #line 2.....              <- other prototypes....
   ......

This patch avoids the situation above by inserting a newline just before
the first `#line` directive if the insertion point happens to be in the
middle of a line.

Fix #7

Author: cmaglie

main.cpp

@@ -197,10 +197,7 @@ class INOPreprocessorMatcherCallback : public MatchFinder::MatchCallback {
 
         FullSourceLoc first = undeclaredIdentifiers.back()->location;
         if (first.isBeforeInTranslationUnitThan(begin)) {
-            if (debugOutput) {
-                outs() << "  !! Insertion point found!\n";
-            }
-            insertionPointFound = true;
+            markInsertionPointAsFound();
             return;
         }
 
@@ -216,10 +213,22 @@ class INOPreprocessorMatcherCallback : public MatchFinder::MatchCallback {
         }
 
         if (first.isBeforeInTranslationUnitThan(end)) {
+            markInsertionPointAsFound();
+        }
+    }
+
+    void markInsertionPointAsFound() {
+        if (debugOutput) {
+            outs() << "  !! Insertion point found at ";
+            outs() << insertionPoint.getSpellingLineNumber() << ":" << insertionPoint.getSpellingColumnNumber() << "\n";
+        }
+        insertionPointFound = true;
+
+        if (insertionPoint.getSpellingColumnNumber() != 1) {
             if (debugOutput) {
-                outs() << "  !! Insertion point found!\n";
+                outs() << "     Insertion point is not at the line beginning -> adding a newline\n";
             }
-            insertionPointFound = true;
+            rewriter.InsertTextAfter(insertionPoint, "\n");
         }
     }