Provide more context to the name of a GPU kernel by prefixing its name with the host function that calls it. E.g. The first kernel called by `kernel_gemm` would be `kernel_gemm_kernel_0`.
This makes it easier to map host caller and device callee, especially when there are many kernels produced by Polly-ACC, all which are called "kernel_#" (# = 0,1,2,3,...).
Previously while profiling kernels generated through JIT e.g. Julia, [[ https://groups.google.com/d/msg/polly-dev/J1j587H3-Qw/mR-jfL16BgAJ | kernels associated with different functions would be grouped together due to the common name ]]. This patch prevents this grouping and the kernels are reported separately.