liblto_plugin-0.dll not found -- arm-none-eabi 4.9 2015q1

EDIT: IMPORTANT -- Turns out the linker does work when installed on a fairly fresh Win7 machine. This includes a fresh install of MinGW make. So, at this point I'm assuming that the problem is somewhere on this old XP machine with who knows what other software in it. I guess I'll leave this post in case someone else is having the same problem.

Original post is as follows:

Using arm-none-eabi-g++ version 4.9.3 (4.9 2015q1) installed as:
C:\Program Files\GNU Tools ARM Embedded\4.9 2015q1

Trying to build a Spark app on a Windows XPSP3 platform. Everything compiles ok, but linker bombs saying liblto_plugin-0.dll not found.

liblto_plugin-0.dll is present in the distribution here:
C:\Program Files\GNU Tools ARM Embedded\4.9 2015q1\lib\gcc\arm-none-eabi\4.9.3

and I've even tried including it in the windows PATH, but still get the error.

make
Building core-common-lib
make[1]: Nothing to be done for `all'.

Building core-communication-lib
make[1]: Nothing to be done for `all'.

Building target: core-firmware.elf
Invoking: ARM GCC C++ Linker
mkdir -p ./
arm-none-eabi-g++ -g3 -gdwarf-2 -Os -mcpu=cortex-m3 -mthumb -I../inc -I../libra
ries/Serial2 -I../../core-common-lib/CMSIS/Include -I../../core-common-lib/CMSIS
/Device/ST/STM32F10x/Include -I../../core-common-lib/STM32F10x_StdPeriph_Driver/
inc -I../../core-common-lib/STM32_USB-FS-Device_Driver/inc -I../../core-common-l
ib/CC3000_Host_Driver -I../../core-common-lib/SPARK_Firmware_Driver/inc -I../../
core-common-lib/SPARK_Services/inc -I../../core-communication-lib/lib/tropicssl/
include -I../../core-communication-lib/src -I. -ffunction-sections -Wall -fmessa
ge-length=0 -Werror=deprecated-declarations -MD -MP -MF core-firmware.elf.d -DUS
E_STDPERIPH_DRIVER -DSTM32F10X_MD -DDFU_BUILD_ENABLE -DSPARK=1 -DRELEASE_BUILD
./obj/src/application.o ./obj/src/main.o ./obj/src/newlib_stubs.o ./obj/src/spar
k_utilities.o ./obj/src/spark_wiring.o ./obj/src/spark_wiring_eeprom.o ./obj/src
/spark_wiring_i2c.o ./obj/src/spark_wiring_interrupts.o ./obj/src/spark_wiring_i
paddress.o ./obj/src/spark_wiring_print.o ./obj/src/spark_wiring_random.o ./obj/
src/spark_wiring_servo.o ./obj/src/spark_wiring_spi.o ./obj/src/spark_wiring_str
eam.o ./obj/src/spark_wiring_string.o ./obj/src/spark_wiring_tcpclient.o ./obj/s
rc/spark_wiring_tcpserver.o ./obj/src/spark_wiring_time.o ./obj/src/spark_wiring
_tone.o ./obj/src/spark_wiring_udp.o ./obj/src/spark_wiring_usartserial.o ./obj/
src/spark_wiring_usbserial.o ./obj/src/spark_wiring_wifi.o ./obj/src/spark_wlan.
o ./obj/src/stm32_it.o ./obj/src/usb_desc.o ./obj/src/usb_endp.o ./obj/src/usb_i
str.o ./obj/src/usb_prop.o ./obj/src/wifi_credentials_reader.o ./obj/src/startup
/startup_stm32f10x_md.o --output core-firmware.elf -T../linker/linker_stm32f10x_
md_dfu.ld -nostartfiles -Xlinker --gc-sections -L../../core-common-lib/build -l
core-common-lib -L../../core-communication-lib/build -lcore-communication-lib -W
l,-Map,core-firmware.map --specs=nano.specs -lc -lnosys -u _printf_float
arm-none-eabi-g++: fatal error: -fuse-linker-plugin, but liblto_plugin-0.dll not
 found
compilation terminated.
make: *** [core-firmware.elf] Error 1

By the way, version 4.8 works ok, and has this dll in the same place in it's distribution.

How do I fix this???
Thanks!

RESOLVED: See top of post