Bug 1802820 - Remove profdata-compat.patch. r=firefox-build-system-reviewers,andi

It was only really needed when we were still using rustc 1.64 (llvm 14),
but now that we have a rustc based on the same llvm version as clang, we
don't need it anymore (and it doesn't apply cleanly on trunk anymore).

Differential Revision: https://phabricator.services.mozilla.com/D163267

build/build-clang/clang-15.json

@@ -14,7 +14,6 @@
         "win64-ret-null-on-commitment-limit_clang_14.patch",
         "llvmorg-16-init-7778-g232e0a011e8c.patch",
         "llvmorg-16-init-10850-gff111a997f1b.patch",
-        "compiler-rt-rss-limit-heap-profile.patch",
-        "profdata-compat.patch"
+        "compiler-rt-rss-limit-heap-profile.patch"
     ]
 }

build/build-clang/clang-trunk.json

@@ -16,7 +16,6 @@
         "revert-llvmorg-14-init-14141-gd6d3000a2f6d.patch",
         "revert-llvmorg-14-init-11890-gf86deb18cab6_clang_16.patch",
         "win64-ret-null-on-commitment-limit_clang_14.patch",
-        "compiler-rt-rss-limit-heap-profile.patch",
-        "profdata-compat.patch"
+        "compiler-rt-rss-limit-heap-profile.patch"
     ]
 }

build/build-clang/profdata-compat.patch

@@ -1,57 +0,0 @@
-https://reviews.llvm.org/D118653 added an optional section to the prof
-format, such that the output of the `llvm-profdata merge` is not readable
-by an older LLVM, such as the one in rustc. Technically speaking,
-the compatibility can be preserved, which we do here.
-
-Alternatively, we could revert that change, but other changes have piled
-up, making a revert more difficult.
-
-diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
-index cd4e8900c963..e553d765bad0 100644
---- a/llvm/lib/ProfileData/InstrProfWriter.cpp
-+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
-@@ -346,7 +346,9 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
-   // Write the header.
-   IndexedInstrProf::Header Header;
-   Header.Magic = IndexedInstrProf::Magic;
--  Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion;
-+  Header.Version = static_cast<bool>(ProfileKind & InstrProfKind::MemProf)
-+                       ? IndexedInstrProf::ProfVersion::CurrentVersion
-+                       : IndexedInstrProf::ProfVersion::Version7;
-   if (static_cast<bool>(ProfileKind & InstrProfKind::IRInstrumentation))
-     Header.Version |= VARIANT_MASK_IR_PROF;
-   if (static_cast<bool>(ProfileKind & InstrProfKind::ContextSensitive))
-@@ -382,7 +384,8 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
-   uint64_t MemProfSectionOffset = OS.tell();
-   // Reserve space for the MemProf table field to be patched later if this
-   // profile contains memory profile information.
--  OS.write(0);
-+  if (static_cast<bool>(ProfileKind & InstrProfKind::MemProf))
-+    OS.write(0);
- 
-   // Reserve space to write profile summary data.
-   uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size();
-@@ -482,8 +485,6 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
-   PatchItem PatchItems[] = {
-       // Patch the Header.HashOffset field.
-       {HashTableStartFieldOffset, &HashTableStart, 1},
--      // Patch the Header.MemProfOffset (=0 for profiles without MemProf data).
--      {MemProfSectionOffset, &MemProfSectionStart, 1},
-       // Patch the summary data.
-       {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()),
-        (int)(SummarySize / sizeof(uint64_t))},
-@@ -492,6 +493,14 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
- 
-   OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems));
- 
-+  if (static_cast<bool>(ProfileKind & InstrProfKind::MemProf)) {
-+    PatchItem PatchItems[] = {
-+        // Patch the Header.MemProfOffset (=0 for profiles without MemProf
-+        // data).
-+        {MemProfSectionOffset, &MemProfSectionStart, 1},
-+    };
-+    OS.patch(PatchItems, sizeof(PatchItems) / sizeof(*PatchItems));
-+  }
-   for (const auto &I : FunctionData)
-     for (const auto &F : I.getValue())
-       if (Error E = validateRecord(F.second))