[llvm] [IRBuilder] Add CreatePtrAdd() method (NFC) (PR #77582)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw commented:

There are other files which create `gep i8`:

> llvm/lib/CodeGen/CodeGenPrepare.cpp line 5600 5612 6200 6253
llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp line 84 87
llvm/lib/CodeGen/SafeStack.cpp line 565 584 619 650
llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp line 865
llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp line 332
llvm/lib/Transforms/IPO/LowerTypeTests.cpp line 676
llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp line 1772 2069 2076
llvm/lib/Transforms/Utils/AMDGPUEmitPrintf.cpp line 128
llvm/unittests/Analysis/BasicAliasAnalysisTest.cpp
llvm/unittests/Analysis/MemorySSATest.cpp


https://github.com/llvm/llvm-project/pull/77582