Update pprof to latest revision (#2096)

* Update pprof to latest revision

Bump from 20191205061153 => 20201109224723

My personal interest is to pull in google/pprof#564, which adds support for displaying names with `"` in them, which julia functions sometimes have (e.g. `var"#foo#23"`)

Includes:
- google/pprof#564
- google/pprof#575
- google/pprof#574
- google/pprof#571
- google/pprof#572
- google/pprof#570
- google/pprof#562
- google/pprof#561
- google/pprof#565
- google/pprof#560
- google/pprof#563
- google/pprof#557
- google/pprof#554
- google/pprof#552
- google/pprof#545
- google/pprof#549
- google/pprof#547
- google/pprof#541
- google/pprof#534
- google/pprof#542
- google/pprof#535
- google/pprof#531
- google/pprof#530
- google/pprof#528
- google/pprof#522
- google/pprof#525
- google/pprof#527
- google/pprof#519
- google/pprof#520
- google/pprof#517
- google/pprof#518
- google/pprof#514
- google/pprof#513
- google/pprof#510
- google/pprof#508
- google/pprof#506
- google/pprof#509
- google/pprof#504

* Update P/pprof/build_tarballs.jl - use a real version number

Co-authored-by: Mosè Giordano <giordano@users.noreply.github.com>

* Remove now unused `timestamp`

* [pprof] Use `GitSource`

Co-authored-by: Mosè Giordano <giordano@users.noreply.github.com>

P/pprof/build_tarballs.jl

@@ -2,18 +2,17 @@ using BinaryBuilder
 
 name = "pprof"
 
-# PProf doesn't have proper versions yet
-# so we use Go's pseudo version
-# `TZ=UTC git show --quiet --date='format-local:%Y%m%d%H%M%S' --format="%cd" $hash`
+# Note that google/pprof doesn't have proper release versions. We are
+# identifying a version by a specific commit hash, off of `pprof`'s
+# main branch.
 
-hash = "f9b734f9ee64d0f5b63636a45cc77ed2744997ab"
-timestamp = "20191205061153"
-version = Base.VersionNumber("0.0.0-$timestamp")
+hash = "20978b51388db0648809a2c5cc88b494c7945ec1"
+version = v"0.1.0"
 
 # Collection of sources required to build pprof
 sources = [
-    "https://github.com/google/pprof.git" =>
-    hash,
+    GitSource("https://github.com/google/pprof.git",
+              hash),
 ]
 
 # Bash recipe for building across all platforms