Fixed linter bug where was thinking catch was a C style cast

The linter script has exceptions to exclude incorrect detection of C
style casts. Added the keyword catch to this list. Added a regression
test to verify this.

regression/cpp-linter/catch-cast/main.cpp

@@ -0,0 +1,12 @@
+/*******************************************************************\
+
+Module: Lint Examples
+
+Author: Thomas Kiley, thomas@diffblue.com
+
+\*******************************************************************/
+
+static fun()
+{
+  catch(int)
+}

regression/cpp-linter/catch-cast/test.desc

@@ -0,0 +1,6 @@
+CORE
+main.cpp
+
+^EXIT=0$
+^SIGNAL=0$
+--

scripts/cpplint.py

@@ -5270,7 +5270,7 @@ def CheckCStyleCast(filename, clean_lines, linenum, cast_type, pattern, error):
 
   # Exclude lines with keywords that tend to look like casts
   context = line[0:match.start(1) - 1]
-  if Match(r'.*\b(?:sizeof|alignof|alignas|[_A-Z][_A-Z0-9]*)\s*$', context):
+  if Match(r'.*\b(?:sizeof|alignof|alignas|catch|[_A-Z][_A-Z0-9]*)\s*$', context):
     return False
 
   # Try expanding current context to see if we one level of