Implement new naming scheme for --target.

Now targets are named like "<isa>-i<mask size>x<gang size>", e.g.
"sse4-i8x16", or "avx2-i32x16".

The old target names are still supported.

util.h

@@ -156,4 +156,18 @@ void GetDirectoryAndFileName(const std::string &currentDir,
 bool VerifyDataLayoutCompatibility(const std::string &module_dl,
                                    const std::string &lib_dl);
 
+/** Print the given string to the given FILE, assuming the given output
+    column width.  Break words as needed to avoid words spilling past the
+    last column.  */
+void PrintWithWordBreaks(const char *buf, int indent, int columnWidth,
+                         FILE *out);
+
+/** Returns the width of the terminal where the compiler is running.
+    Finding this out may fail in a variety of reasonable situations (piping
+    compiler output to 'less', redirecting output to a file, running the
+    compiler under a debuffer; in this case, just return a reasonable
+    default.
+ */
+int TerminalWidth();
+
 #endif // ISPC_UTIL_H