INSTALL.md: Fix SC_CPLUSPLUS value for C++03

[richardxia]

INSTALL.md incorrectly described the SC_CPLUSPLUS value for C++03 as 199701L. This value comes directly from the C++ specification, and it should actually be set to 199711L for C++98 and C++03.

I discovered this problem when trying to compile a C++ project with C++11 against a version of the SystemC (2.3.3) library compiled against the C++03 standard. My attempts at setting the SC_CPLUSPLUS macro failed to work until I discovered that the correct value is actually 199711L, from this StackOverflow post: https://stackoverflow.com/a/11054055.

I'd like to submit this simple correction to INSTALLmd to help others who may have encountered issues with trying to override this value.

[markfoodyburton]

Hi, thanks for your contribution, would you mind adding a brief description to the commit message and a signed-of-by line, with your affiliation.

For your contribution to be applicable for consideration by the Accellera working groups, you need to sign-off the Accellera Developer's Certificate of Origin as described in the CONTRIBUTING file.

Thanks

[richardxia]

Thanks, I amended my commit to add a signed-off-by line. My original commit did have a description, so I didn't change anything about it, but please let me know if you were looking for more detail on anything in particular.

[markfoodyburton]

Thanks !

[roccojonack]

The fix seems correct. Probably not too many pre C++11 project out there any more, but I would agree with the patch.