Fix broken -emit-spirv-via-glsl test option (#7091)

Fixes issue #6898

The -emit-spirv-via-glsl slang-test option has been broken for
some amount of time. Tests that were using it were operating as
if using -emit-spirv-directly, leading to many duplicated tests.

After fixing the test option, there were an number of errors that
appeared as a result.

This change fixes the broken test option and the resulting test
errors. Some of the test errors revealed some legitimate issues,
such as:

-The GLSL bitCount instrinsic only supports 32-bit integers and
 requires emulation for other bit widths.
-Emitting GLSL 8-bit and 16-bit glsl integer types did not emit
 the proper extension requirements
-Emitting GLSL and casting for 16-bit integers was missing a
 closing parenthesis.
-Missing profile for GL_EXT_shader_explicit_arithmetic_types
-Missing toType cases for UInt8/Int8 for the kIROp_BitCast case
 in tryEmitInstExprImpl.

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/language-feature/bitfield/bitfield-insert-extract-non32bit.slang b/tests/language-feature/bitfield/bitfield-insert-extract-non32bit.slang
index 0edbb049a..ded0baed4 100644
--- a/tests/language-feature/bitfield/bitfield-insert-extract-non32bit.slang
+++ b/tests/language-feature/bitfield/bitfield-insert-extract-non32bit.slang
@@ -1,4 +1,4 @@
-//TEST:COMPARE_COMPUTE(filecheck-buffer=BUF): -vk -output-using-type
+//TEST:COMPARE_COMPUTE(filecheck-buffer=BUF): -vk -output-using-type -emit-spirv-directly
 //TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0], stride=4):out,name=outputBuffer
 RWStructuredBuffer<int32_t> outputBuffer;