[LinkerWrapper] Allow 'all' as a generic bundled architecture (#81193)

Summary:
Currently, the linker wrapper sorts input files into different link
jobs according to their architectures. Here we assume each architecture
is a unique and incompatible link job unless they are specifically
marked compatible. This patch simply adds an `all` target to represent
an architecture that should be linked against every single other
architecture.

This will be useful for modelling generic IR such as the ROCm device
libraries or the NVPTX libdevice.

Author: jhuber6

clang/test/Driver/linker-wrapper.c

@@ -172,6 +172,22 @@ __attribute__((visibility("protected"), used)) int x;
 // AMD-TARGET-ID: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a:xnack+ -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
 // AMD-TARGET-ID: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a:xnack- -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
 
+// RUN: clang-offload-packager -o %t-lib.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=all
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t.o -fembed-offload-object=%t-lib.out
+// RUN: llvm-ar rcs %t.a %t.o
+// RUN: clang-offload-packager -o %t1.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx90a
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t1.o -fembed-offload-object=%t1.out
+// RUN: clang-offload-packager -o %t2.out \
+// RUN:   --image=file=%t.elf.o,kind=openmp,triple=amdgcn-amd-amdhsa,arch=gfx908
+// RUN: %clang -cc1 %s -triple x86_64-unknown-linux-gnu -emit-obj -o %t2.o -fembed-offload-object=%t2.out
+// RUN: clang-linker-wrapper --host-triple=x86_64-unknown-linux-gnu --dry-run \
+// RUN:   --linker-path=/usr/bin/ld -- %t1.o %t2.o %t.a -o a.out 2>&1 | FileCheck %s --check-prefix=ARCH-ALL
+
+// ARCH-ALL: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx908 -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
+// ARCH-ALL: clang{{.*}} -o {{.*}}.img --target=amdgcn-amd-amdhsa -mcpu=gfx90a -O2 -Wl,--no-undefined {{.*}}.o {{.*}}.o
+
 // RUN: clang-offload-packager -o %t.out \
 // RUN:   --image=file=%t.elf.o,kind=openmp,triple=x86_64-unknown-linux-gnu \
 // RUN:   --image=file=%t.elf.o,kind=openmp,triple=x86_64-unknown-linux-gnu

llvm/lib/Object/OffloadBinary.cpp

@@ -355,6 +355,10 @@ bool object::areTargetsCompatible(const OffloadFile::TargetID &LHS,
   if (LHS.first != RHS.first)
     return false;
 
+  // If the architecture is "all" we assume it is always compatible.
+  if (LHS.second.equals("all") || RHS.second.equals("all"))
+    return true;
+
   // Only The AMDGPU target requires additional checks.
   llvm::Triple T(LHS.first);
   if (!T.isAMDGPU())