perl: fix build errors on macOS

Added a check for macOS 11 and newer to resolve a compile error:
*** Unexpected product version 11.2.

Added Internals::getcwd.
Fallback to the built-in getcwd to resolve compile errors on macOS:
Can't locate Errno.pm in @INC
/miniperl not found

Signed-off-by: Georgi Valkov <gvalkov@abv.bg>

lang/perl/patches/001-macos_11_support.patch

@@ -0,0 +1,29 @@
+--- a/hints/darwin.sh
++++ b/hints/darwin.sh
+@@ -301,7 +301,7 @@ case "$osvers" in  # Note: osvers is the
+    # We now use MACOSX_DEPLOYMENT_TARGET, if set, as an override by
+    # capturing its value and adding it to the flags.
+     case "$MACOSX_DEPLOYMENT_TARGET" in
+-    10.*)
++    [1-9][0-9].*)
+       add_macosx_version_min ccflags $MACOSX_DEPLOYMENT_TARGET
+       add_macosx_version_min ldflags $MACOSX_DEPLOYMENT_TARGET
+       ;;
+@@ -313,7 +313,7 @@ case "$osvers" in  # Note: osvers is the
+ 
+ *** Unexpected MACOSX_DEPLOYMENT_TARGET=$MACOSX_DEPLOYMENT_TARGET
+ ***
+-*** Please either set it to 10.something, or to empty.
++*** Please either set it to a valid macOS version number (e.g., 10.15) or to empty.
+ 
+ EOM
+       exit 1
+@@ -327,7 +327,7 @@ EOM
+     # "ProductVersion:    10.11"     "10.11"
+         prodvers=`sw_vers|awk '/^ProductVersion:/{print $2}'|awk -F. '{print $1"."$2}'`
+     case "$prodvers" in
+-    10.*)
++    [1-9][0-9].*)
+       add_macosx_version_min ccflags $prodvers
+       add_macosx_version_min ldflags $prodvers
+       ;;