[Utils] Add URL formatting for revert_checker

MemoryBuiltins: update comment; NFC

bugprone-argument-comment: ignore mismatches from system headers

security: highlight phab accounts; recommend phab for nominations

[clang] Evaluate strlen of strcpy argument for -Wfortify-source.

llvm/utils: guarantee revert_checker's revert ordering

[Sema] attempt to appease buildbots after r367940

[Sema] Add -Wpointer-compare

[Sema] add -Walloca to flag uses of `alloca`

[BasicAA] Temporarily disable two tests

Fix a typo in target features

clang-format a block; NFC

[Targets] Move soft-float-abi filtering to `initFeatureMap`

android: add a close-on-exec check on pipe()

android: add a close-on-exec check on pipe2()

CFLAA: reflow comments; NFC

Remove unnecessary const&s; NFC

Remove unnecessary const&s; NFC

Various fixes and additions to creduce-clang-crash.py

Various fixes and additions to creduce-clang-crash.py

[MSSA] Delete move ctor; remove dynamic never-moved verification

creduce-clang-crash.py: preprocess file + reduce commandline

creduce-clang-crash.py: preprocess file + reduce commandline

Add a creduce script for clang crashes

Add a creduce script for clang crashes

[CFLAnders] Fix typo in comment; NFC

Remove a redundant space from an error message; NFC

[LoopIdioms] More LocationSize::precise annotations; NFC

[SelectionDAGBuilder] Use ::precise LocationSizes; NFC

[MemCpyOpt] Use LocationSize instead of ints; NFC

[MemoryLocation] Use LocationSize instead of ints; NFC

[Loads] Use LocationSize instead of ints; NFC

[Lint] Use LocationSize instead of ints; NFC

[AAEval] Use LocationSize instead of ints; NFC

[Analysis] More LocationSize cleanup; NFC

[Analysis] s/uint64_t/LocationSize; NFC

[ModuleSummary] use StringRefs to avoid a redundant copy; NFC

[ThinLTO] Look through aliases when computing hash keys

[InlineCost] Remove a dead constant; NFC

[utils] Run tests in the proper directory.

Add docs+a script for building clang/LLVM with PGO

Replace most users of UnknownSize with LocationSize::unknown(); NFC

[Analysis] Make LocationSizes carry an 'imprecise' bit

[Analysis] Make LocationSize pretty-printing more descriptive

Make LocationSize a proper Optional type; NFC

Use locals instead of struct fields; NFC

[PartiallyInlineLibCalls] Add DebugCounter support

[DCE] Add DebugCounter support

[MemorySSA] Add NDEBUG checks to verifiers; NFC

s/std::set/DenseSet/; NFC

[MemorySSA] Fix def optimization handling

[MemorySSA] Invalidate optimized Defs upon moving them; NFC

[MemorySSA] Move two simple getters; NFC

[DebugCounters] don't do redundant map lookups; NFC

[Metadata] Replace a SmallVector with an array; NFC

[MemorySSA] "Fix" lifetime intrinsic handling

Use Optional instead of unique_ptr; NFC

Use Optional instead of unique_ptr; NFC

[Support] Add an enable bit to our DebugCounters

Reland r338431: "Add DebugCounters to DivRemPairs"

Revert r338431: "Add DebugCounters to DivRemPairs"

Add DebugCounters to DivRemPairs

Fix unused variable warnings; NFC

Fix unused variable warnings; NFC

[DebugCounters] Keep track of total counts

Remove redundant *_or_null checks; NFC

Sort includes + include a missing `extern "C"` header

Make llvm.objectsize more conservative with null

[Parse] Make -Wgcc-compat complain about for loop inits in C89

[Parse] Make -Wgcc-compat complain about for loop inits in C89

[MSSA] Add domination number verifier; NFC

[MSSA] Remove incorrect comment + `auto`ify dyn_cast results; NFC

[MSSA] Print more optimization information

Simplify; NFC