[llvm-lit] lit internal shell failing to parse and execute for-loop syntax

[connieyzhu]

lit’s internal shell cannot recognize and execute for loop syntax, which is used in tests across compiler-rt.

Example error message:

FAIL: libFuzzer-i386-libcxx-Linux :: features_dir.test (14 of 9570)
******************** TEST 'libFuzzer-i386-libcxx-Linux :: features_dir.test' FAILED ********************
Exit Code: 127

Command Output (stdout):

# RUN: at line 7
for c in /usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/fuzzer/I386LibcxxLinuxConfig/Output/features_dir.test.tmp-C/*; do f=/usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/fuzzer/I386LibcxxLinuxConfig/Output/features_dir.test.tmp-F/$(basename $c); echo looking for $f; [ -a $f ]; done
# executed command: for c in '/usr/local/google/home/harinidonthula/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/fuzzer/I386LibcxxLinuxConfig/Output/features_dir.test.tmp-C/*'
# .---command stderr------------
# | 'for': command not found
# `-----------------------------
# error: command failed with exit status: 127