build-llvm: Install and keep llvm-lib

It's an equivalent to MSVC lib.exe [^1].

It is used by meson to find the DLL name from a .lib/.dll.a [^2].
The other option is dlltool, which is not the same as llvm-dlltool.

[^1] https://llvm.org/docs/CommandGuide/llvm-lib.html
[^2] https://github.com/mesonbuild/meson/blob/1e986554ef2071f59fb796cda5e66c448bde6ac9/mesonbuild/scripts/symbolextractor.py#L209

build-llvm.sh

@@ -312,7 +312,7 @@ cmake \
     -DLLVM_TARGETS_TO_BUILD="ARM;AArch64;X86;NVPTX" \
     -DLLVM_INSTALL_TOOLCHAIN_ONLY=$TOOLCHAIN_ONLY \
     -DLLVM_LINK_LLVM_DYLIB=$LINK_DYLIB \
-    -DLLVM_TOOLCHAIN_TOOLS="llvm-ar;llvm-ranlib;llvm-objdump;llvm-rc;llvm-cvtres;llvm-nm;llvm-strings;llvm-readobj;llvm-dlltool;llvm-pdbutil;llvm-objcopy;llvm-strip;llvm-cov;llvm-profdata;llvm-addr2line;llvm-symbolizer;llvm-windres;llvm-ml;llvm-readelf;llvm-size;llvm-cxxfilt" \
+    -DLLVM_TOOLCHAIN_TOOLS="llvm-ar;llvm-ranlib;llvm-objdump;llvm-rc;llvm-cvtres;llvm-nm;llvm-strings;llvm-readobj;llvm-dlltool;llvm-pdbutil;llvm-objcopy;llvm-strip;llvm-cov;llvm-profdata;llvm-addr2line;llvm-symbolizer;llvm-windres;llvm-ml;llvm-readelf;llvm-size;llvm-cxxfilt;llvm-lib" \
     ${HOST+-DLLVM_HOST_TRIPLE=$HOST} \
     $CMAKEFLAGS \
     ..

install-wrappers.sh

@@ -97,7 +97,7 @@ if [ -n "${HOST_CLANG}" ]; then
     llvmexec="$PATH:$llvmdir/bin"
 
     for exec in ld.lld llvm-ar llvm-ranlib llvm-nm llvm-objcopy llvm-strip llvm-rc llvm-cvtres \
-                llvm-addr2line llvm-dlltool llvm-readelf llvm-size llvm-strings llvm-addr2line llvm-windres llvm-ml; do
+                llvm-addr2line llvm-dlltool llvm-readelf llvm-size llvm-strings llvm-addr2line llvm-windres llvm-ml llvm-lib; do
         execpath=$(PATH=$llvmexec command -v $exec) && ln -sf $execpath $PREFIX/bin/$exec
     done
 fi

strip-llvm.sh

@@ -89,7 +89,7 @@ for i in amdgpu-arch bugpoint c-index-test clang-* clangd clangd-* darwin-debug
             rm -f $i
         fi
         ;;
-    llvm-ar|llvm-cvtres|llvm-dlltool|llvm-nm|llvm-objdump|llvm-ranlib|llvm-rc|llvm-readobj|llvm-strings|llvm-pdbutil|llvm-objcopy|llvm-strip|llvm-cov|llvm-profdata|llvm-addr2line|llvm-symbolizer|llvm-wrapper|llvm-windres|llvm-ml|llvm-readelf|llvm-size|llvm-cxxfilt)
+    llvm-ar|llvm-cvtres|llvm-dlltool|llvm-nm|llvm-objdump|llvm-ranlib|llvm-rc|llvm-readobj|llvm-strings|llvm-pdbutil|llvm-objcopy|llvm-strip|llvm-cov|llvm-profdata|llvm-addr2line|llvm-symbolizer|llvm-wrapper|llvm-windres|llvm-ml|llvm-readelf|llvm-size|llvm-cxxfilt|llvm-lib)
         ;;
     ld64.lld|wasm-ld)
         if [ -e $i ]; then