Program::shader() was taking a string before which didn't make sense
for spirv. Now it's just a blob, in the case of GL/Metal, the blob
must be a null terminated c-string, and the size must include the
terminating null character.
This fixes an out-of-bound access in ShaderBuilder::getShader() (which
doesn't exist anymore), because it was creating a CString passing
a size that included the null terminating char, which is not was CString
expects. CString can now assert() in that case.
driver::Program now uses a std::vector<> for storage, which we should
fix at some point (b/c it's a public header). CString was not suited to
store binary blobs.
f2ba48f4a7