Fix a problem where older IRIX compilers needed a typecast for certain opperations

simgear/compatibility/IRIX

@@ -0,0 +1,43 @@
+
+#ifndef __SGI_HXX
+#define __SGI_HXX
+
+#include <string>
+
+inline bool
+operator!=( const std::string& lhs, const char* rhs)
+{
+    return lhs.compare( rhs ) != 0;
+}
+
+inline bool
+operator!=( const char* lhs, const std::string& rhs)
+{
+    return rhs.compare( lhs ) != 0;
+}
+
+inline bool
+operator==( const std::string& lhs, const char* rhs)
+{
+    return lhs.compare( rhs ) == 0;
+}
+
+inline bool
+operator==( const char* lhs, const std::string& rhs)
+{
+    return rhs.compare( lhs ) == 0;
+}
+
+inline std::string
+operator+(const std::string& lhs, const char* rhs)
+{
+    return lhs + std::string(rhs);
+}
+
+inline std::string
+operator+(const char* lhs, const std::string& rhs)
+{
+    return std::string(lhs) + rhs;
+}
+
+#endif // !__SGI_HXX

simgear/compatibility/Makefile.am

@@ -28,4 +28,6 @@ include_HEADERS	= \
 	ctime \
 	iomanip \
 	new \
-	streambuf
+	streambuf \
+	\
+	IRIX