[WebAssembly] Update know failures for the wasm waterfall

[sbc100]

Summary

The waterfall no longer builds .s files and no longers uses
the wasm-o when it builds object files.

lib/Target/WebAssembly/known_gcc_test_failures.txt

 # Tests which are known to fail from the GCC torture test suite.
 
 # Syntax: Each line has a single test to be marked as a 'known failure' (or
 # 'exclusion'. Known failures are expected to fail, and will cause an error if
 # they pass. (Known failures that do not run at all will not cause an
 # error). The format is
 # <name> <attributes> # comment
-#
-# The attributes in this case represent the different arguments used to
-# compiler: 'wasm-s' is for compiling to .s files, and 'wasm-o' for compiling
-# to wasm object files (.o).
 
 # Computed gotos are not supported (Cannot select BlockAddress/BRIND)
-20071220-1.c wasm-o
-20071220-2.c wasm-o
[phone].c
[phone].c
 20040302-1.c
 20041214-1.c O0
 20071210-1.c
-20071220-1.c wasm-s,O0
 920501-4.c
 920501-5.c
 comp-goto-1.c
 980526-1.c
 990208-1.c
 label13.C O0
 label13a.C O0
 label3.C