devel/llvm15: arm fixes, lite default change

Change the lite flavor to default to BE_FREEBSD rather than BE_NATIVE to
allow its use in cross-build CI pipelines.

Backport fix for LLVM bug 61396. [0]  This fixes miscompilation of gcc
on 32-bit arm.

Remove an obsolete patch which breaks arm64. [1]

PR:		271992 [0], 271616 [1]
Reported by:	jfc@mit.edu [0,1]

devel/llvm15/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	llvm
 DISTVERSION=	15.0.7
-PORTREVISION=	3
+PORTREVISION=	4
 CATEGORIES=	devel lang
 MASTER_SITES=	https://github.com/llvm/llvm-project/releases/download/llvmorg-${DISTVERSION:S/rc/-rc/}/ \
 		https://${PRE_}releases.llvm.org/${LLVM_RELEASE}${RCDIR}/
@@ -97,7 +97,7 @@ OPTIONS_SINGLE_BACKENDS=BE_FREEBSD BE_NATIVE BE_STANDARD
 OPTIONS_SUB=	yes
 
 .if ${FLAVOR:Mlite}
-OPTIONS_DEFAULT+=	BE_NATIVE
+OPTIONS_DEFAULT+=	BE_FREEBSD
 .else
 OPTIONS_DEFINE+=	EXTRAS FLANG LIT LLDB MLIR OPENMP PYCLANG
 OPTIONS_DEFINE_aarch64=	OPENMP

devel/llvm15/files/patch-backport-962c306a1

@@ -0,0 +1,42 @@
+commit 8e1222aee4c657e572b7d7841daf7f48ec6ba035
+Author: John F. Carr <jfc@mit.edu>
+Date:   Tue Jun 13 14:10:00 2023 -0400
+
+    LLVM commit 962c306a11d0a21c884c12e18825b8a41ba1bd7d
+
+diff --git a/contrib/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/contrib/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+index 5fd4e45d80fb..9d95cb25efa0 100644
+--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
++++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+@@ -4627,11 +4627,17 @@ void LoopVectorizationCostModel::collectLoopUniforms(ElementCount VF) {
+             WideningDecision == CM_Interleave);
+   };
+
+-
+   // Returns true if Ptr is the pointer operand of a memory access instruction
+-  // I, and I is known to not require scalarization.
++  // I, I is known to not require scalarization, and the pointer is not also
++  // stored.
+   auto isVectorizedMemAccessUse = [&](Instruction *I, Value *Ptr) -> bool {
+-    return getLoadStorePointerOperand(I) == Ptr && isUniformDecision(I, VF);
++    auto GetStoredValue = [I]() -> Value * {
++      if (!isa<StoreInst>(I))
++        return nullptr;
++      return I->getOperand(0);
++    };
++    return getLoadStorePointerOperand(I) == Ptr && isUniformDecision(I, VF) &&
++           GetStoredValue() != Ptr;
+   };
+
+   // Holds a list of values which are known to have at least one uniform use.
+@@ -4679,8 +4685,8 @@ void LoopVectorizationCostModel::collectLoopUniforms(ElementCount VF) {
+       if (isa<LoadInst>(I) && Legal->isUniformMemOp(I))
+         addToWorklistIfAllowed(&I);
+
+-      if (isUniformDecision(&I, VF)) {
+-        assert(isVectorizedMemAccessUse(&I, Ptr) && "consistency check");
++      if (isVectorizedMemAccessUse(&I, Ptr)) {
++        assert(isUniformDecision(&I, VF) && "consistency check");
+         HasUniformUse.insert(Ptr);
+       }
+     }