Add the name of the forEach functions to the tracing output

Instead of showing up as 'runForEach', kernels are now e.g. printed as
'runForEach_createAntLookup'.

The String8 is carefully constructed here, such that we only pay
the string processing overhead in case tracing is actually enabled.

Change-Id: Id18319e271a02cbe888bcb9fe806794007d00fca
3 files changed