Added buffer in get_ch() for line continuation lookahead #402

Job	Run time
catch-bad-whitespace	4s
bootstrap-pnut-sh (bash)	1m 26s
bootstrap-pnut-exe (bash, i386_linux)	2m 16s
bootstrap-pnut-sh (dash)	1m 53s
build-without-warnings	29s
bootstrap-pnut-exe (bash, x86_64_linux)	2m 17s
tests-exe (i386_linux, ubuntu-latest)	12s
bootstrap-pnut-sh (ksh)	50s
bootstrap-pnut-exe (bash, x86_64_mac)	2m 8s
tests-exe (x86_64_linux, ubuntu-latest)	10s
bootstrap-pnut-sh (mksh)	2m 18s
tests-shell (bash)	23s
bootstrap-pnut-exe (dash, i386_linux)	1m 49s
tests-exe (x86_64_mac, macos-latest)	13s
bootstrap-pnut-sh (yash)	2m 17s
tests-shell (dash)	16s
bootstrap-pnut-exe (dash, x86_64_linux)	1m 48s
bootstrap-pnut-sh (zsh)	2m 18s
bootstrap-pnut-exe (dash, x86_64_mac)	2m 4s
tests-shell (ksh)	25s
tests-shell (mksh)	39s
bootstrap-pnut-exe (ksh, i386_linux)	1m 47s
tests-shell (yash)	38s
bootstrap-bash-2_05a	2m 18s
bootstrap-pnut-exe (ksh, x86_64_linux)	1m 47s
tests-shell (zsh)	24s
bootstrap-pnut-exe (ksh, x86_64_mac)	1m 22s
bootstrap-pnut-sh-with-pnut-exe (i386_linux)	13s
pnut-variants-run (reader)	20s
compile-in-safe-mode	16s
bootstrap-pnut-sh-with-pnut-exe (x86_64_linux)	10s
pnut-variants-run (tokenizer)	37s
bootstrap-pnut-sh-with-pnut-exe (x86_64_mac)	16s
pnut-variants-run (parser)	46s
success-message	1s
	37m 10s

Provide feedback