Tools check for Arm Compiler 5 in PATH when compiling with Arm Compiler 6

[bridadan]

Description

@SenRamakri

I'm using commit 83d7019 of master at the moment:

$ mbed import https://github.com/armmbed/mbed-os-example-blinky
$ cd mbed-os-example-blinky/mbed-os
$ git fetch origin master
$ git checkout origin/master
$ cd ../
$ mbed compile -m K64F -t ARM
[mbed] WARNING: If you're using Python 3 with Mbed OS 5.8 and earlier versions, Python errors will occur when compiling, testing and exporting
---
[mbed] Working path "C:\Users\bridan01\onedrive_arm\Documents\dev\mbed-os-example-blinky" (program)
usage: make.py [-h] [-m MCU] [--custom-targets CUSTOM_TARGETS_DIRECTORY]
               [-t TOOLCHAIN] [--color] [--cflags CFLAGS]
               [--asmflags ASMFLAGS] [--ldflags LDFLAGS] [-c]
               [--profile PROFILE] [--app-config APP_CONFIG]
               [-p PROGRAM | -n PROGRAM | -L | -S [{matrix,toolchains,targets}]]
               [-j JOBS] [-v] [--silent] [-D MACROS] [-f GENERAL_FILTER_REGEX]
               [--stats-depth STATS_DEPTH] [--automated] [--host HOST_TEST]
               [--extra EXTRA] [--peripherals PERIPHERALS]
               [--dep DEPENDENCIES] [--source SOURCE_DIR]
               [--duration DURATION] [--build BUILD_DIR] [-N ARTIFACT_NAME]
               [--ignore IGNORE] [-b BAUD] [--rpc] [--usb] [--dsp] [--testlib]
               [--build-data BUILD_DATA] [-l LINKER_SCRIPT]
make.py: error: Could not find executable for ARM.
Currently set search path: No path set
[mbed] ERROR: "C:\Users\bridan01\AppData\Local\Programs\Python\Python36-32\python.exe" returned error.
       Code: 2
       Path: "C:\Users\bridan01\onedrive_arm\Documents\dev\mbed-os-example-blinky"
       Command: "C:\Users\bridan01\AppData\Local\Programs\Python\Python36-32\python.exe -u C:\Users\bridan01\onedrive_arm\Documents\dev\mbed-os-example-blinky\mbed-os\tools\make.py -t ARM -m K64F --source . --build .\BUILD\K64F\ARM"
       Tip: You could retry the last command with "-v" flag for verbose output
---
[mbed] WARNING: Using Python 3 with Mbed OS 5.8 and earlier can cause errors with compiling, testing and exporting
---

$ where armclang
C:\Program Files\ARMCompiler6.11\bin\armclang.exe
$ where armcc
INFO: Could not find files for the given pattern(s).

As you can see, Arm Compiler 6 is in my path but Arm Compiler 5 is not. I believe the tools are still checking Arm Compiler 5 still.

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-984