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 gemm would be FUNC_gemm_KERNEL_0.
Kernels currently follow the "kernel_#" (# = 0,1,2,3,...) nomenclature. This patch makes it easier to map host caller and device callee, especially when there are many kernels produced by Polly-ACC.