Spaces are useful to separate independent constructs, but can cause
confusion when added between dependent ones. For example "a*b [i]"
is hard for humans to read correctly at a glance. "a*b[i]" is better,
and "a * b[i]" is the easiest to understand immediately.

Control statements are no different. "if (a)if (b)x;" is hard to parse.
"if (a) if (b) x;" is better, but "if(a) if(b) x;" leaves no confusion
of what belongs where.

This recommendation also follows the 'zero one infinity' rule of thumb:
https://en.wikipedia.org/wiki/Zero_one_infinity_rule
Whether we write "a + b" or "a  +  b", they are equally readable, and
the additional spaces may help with alignment of surrounding
expressions. "for  (int i : c)" on the other hand makes the keyword
unintentionally even more dissociated from its header than
"for (int i : c)" already does.

The argument that the space helps set it apart from function calls seems
moot when practically every editor supports keyword highlighting,
function names are typically longer than 2-3 characters, and function
calls are not followed by curly brackets (which while optional for
singular statements, are still recommended for reasons other than this
one).

Bug: b/144825072
Change-Id: I3432fadae8e5604123f5c537097323504fecbc8c
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39588Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>