mitigate spectre variant 2 and 4 using middleware language and not low level assembly

I am looking for implementing a custom software function in c/c++ that will mitigate spectre variant 2 and 4 ,

Variant 4 is CVE-2017-5754 Rogue Data Access

Variant 2 is (CVE-2017-5715) Branch target injection

I have a query on spectre insecurity threats to modern Intel CPUs on Windows OS. CVE-2017-5715, also known as spectre variant 2. Branch target injection spectre variant 2 can be mitigated using retpoline. I am unable to implement retpoline in c/c++ function. Can some one help?

I have seen retpoline solutions implemented in low level assemble language instructions posted on internet sites . Is it possible to implement retpoline using middleware language c/c++ and not low level assembly? Also to mitigate Variant 4 is CVE-2017-5754 Rogue Data Access using  middleware language?

regards

sachin