commit 619aea23b10acabc08332e9ff2b0f51221d0743d
Author: Jan Vorlicek <jan.vorlicek@volny.cz>
Date:   Tue Nov 30 10:55:21 2021 +0100

    Fix clang 13 induced runtime issues (#62170)
    
    The clang 13 optimizer started to assume that "this" pointer is always
    properly aligned. That lead to elimination of some code that was actually
    needed.
    It also takes pointer aliasing rules more strictly in one place in jit.
    That caused the optimizer to falsely assume that a callee with an argument
    passed by reference is not modifying that argument and used a stale
    copy of the original value at the caller site.
    
    This change fixes both of the issues. With this fix, runtime compiled
    using clang 13 seems to be fully functional.
    
    (cherry picked from commit a47e5d1a3cf2bf39368ee6eab7929c7a8e9f3222)
    
    Conflicts:
            src/coreclr/jit/bitsetasshortlong.h

diff --git a/src/coreclr/inc/corhlpr.h b/src/coreclr/inc/corhlpr.h
index 450514da95c..427e8cdc0ff 100644
--- a/src/coreclr/inc/corhlpr.h
+++ b/src/coreclr/inc/corhlpr.h
@@ -336,7 +336,7 @@ struct COR_ILMETHOD_SECT
     const COR_ILMETHOD_SECT* Next() const
     {
         if (!More()) return(0);
-        return ((COR_ILMETHOD_SECT*)(((BYTE *)this) + DataSize()))->Align();
+        return ((COR_ILMETHOD_SECT*)Align(((BYTE *)this) + DataSize()));
     }
 
     const BYTE* Data() const
@@ -374,9 +374,9 @@ struct COR_ILMETHOD_SECT
         return((AsSmall()->Kind & CorILMethod_Sect_FatFormat) != 0);
     }
 
-    const COR_ILMETHOD_SECT* Align() const
+    static const void* Align(const void* p)
     {
-        return((COR_ILMETHOD_SECT*) ((((UINT_PTR) this) + 3) & ~3));
+        return((void*) ((((UINT_PTR) p) + 3) & ~3));
     }
 
 protected:
@@ -579,7 +579,7 @@ typedef struct tagCOR_ILMETHOD_FAT : IMAGE_COR_ILMETHOD_FAT
 
     const COR_ILMETHOD_SECT* GetSect() const {
         if (!More()) return (0);
-        return(((COR_ILMETHOD_SECT*) (GetCode() + GetCodeSize()))->Align());
+        return(((COR_ILMETHOD_SECT*) COR_ILMETHOD_SECT::Align(GetCode() + GetCodeSize())));
     }
 } COR_ILMETHOD_FAT;
 
diff --git a/src/coreclr/jit/bitsetasshortlong.h b/src/coreclr/jit/bitsetasshortlong.h
index dce54d6a5ca..365cf346a10 100644
--- a/src/coreclr/jit/bitsetasshortlong.h
+++ b/src/coreclr/jit/bitsetasshortlong.h
@@ -345,7 +345,7 @@ public:
     {
         if (IsShort(env))
         {
-            (size_t&)out = (size_t)out & ((size_t)gen | (size_t)in);
+            out = (BitSetShortLongRep)((size_t)out & ((size_t)gen | (size_t)in));
         }
         else
         {
@@ -361,7 +361,7 @@ public:
     {
         if (IsShort(env))
         {
-            (size_t&)in = (size_t)use | ((size_t)out & ~(size_t)def);
+            in = (BitSetShortLongRep)((size_t)use | ((size_t)out & ~(size_t)def));
         }
         else
         {