[Fix] remove `nvm_supports_source_options`

Fixes #2387
diff --git a/nvm.sh b/nvm.sh
index 2f59708..9635062 100644
--- a/nvm.sh
+++ b/nvm.sh
@@ -3931,7 +3931,7 @@
         nvm_has_system_node nvm_has_system_iojs \
         nvm_download nvm_get_latest nvm_has nvm_install_default_packages nvm_get_default_packages \
         nvm_curl_use_compression nvm_curl_version \
-        nvm_supports_source_options nvm_auto nvm_supports_xz \
+        nvm_auto nvm_supports_xz \
         nvm_echo nvm_err nvm_grep nvm_cd \
         nvm_die_on_prefix nvm_get_make_jobs nvm_get_minor_version \
         nvm_has_solaris_binary nvm_is_merged_node_version \
@@ -4013,14 +4013,6 @@
   fi
 }
 
-nvm_supports_source_options() {
-  # shellcheck disable=SC1091,SC2240
-    [ "_$( . /dev/stdin yes 2> /dev/null <<'EOF'
-[ $# -gt 0 ] && nvm_echo $1
-EOF
-  )" = "_yes" ]
-}
-
 nvm_supports_xz() {
   if [ -z "${1-}" ]; then
     return 1
@@ -4108,15 +4100,13 @@
 nvm_process_parameters() {
   local NVM_AUTO_MODE
   NVM_AUTO_MODE='use'
-  if nvm_supports_source_options; then
-    while [ $# -ne 0 ]; do
-      case "$1" in
-        --install) NVM_AUTO_MODE='install' ;;
-        --no-use) NVM_AUTO_MODE='none' ;;
-      esac
-      shift
-    done
-  fi
+  while [ $# -ne 0 ]; do
+    case "$1" in
+      --install) NVM_AUTO_MODE='install' ;;
+      --no-use) NVM_AUTO_MODE='none' ;;
+    esac
+    shift
+  done
   nvm_auto "${NVM_AUTO_MODE}"
 }
 
diff --git a/test/fast/Unit tests/nvm_supports_source_options b/test/fast/Unit tests/nvm_supports_source_options
deleted file mode 100755
index ceeff91..0000000
--- a/test/fast/Unit tests/nvm_supports_source_options
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/sh
-
-die () { echo "$@" ; exit 1; }
-
-\. ../../../nvm.sh
-
-x=0
-i=0
-runs=5
-calls=500
-first_result=false
-if (nvm_supports_source_options && printf .); then
-  first_result=true
-fi
-while [ $x -le $runs ]; do
-  y=$x
-  x=$(( x + 1 ))
-  while [ $i -le $calls ]; do
-    this_result=false
-    if (nvm_supports_source_options && printf .); then
-      this_result=true
-    fi
-    [ $this_result = $first_result ] || die "call ${i}, run ${y} got ${this_result}; expected ${first_result}"
-    i=$(( i + 1 ))
-  done
-done
-echo "${runs} runs of ${calls} calls succeeded"