Mangle function names as a separate step before emitting func-bodies.

This is necessary to support function calls in FP files properly; in
some cases, functions can be referenced before they have been emitted,
and we need to be able to name them.

This CL resolves the remaining errors in GrRecursion.cpp. There are
still additional errors in GrNestedCall.cpp that will be fixed in
followup CLs.

Change-Id: Iec98ef02ea6a98a9945a4e0e3cfa3537dff01305
Bug: skia:10684, skia:10872
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/329676
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
14 files changed